Nov. 2023, 公益社団法人 日本缶詰びん詰めレトルト食品協会, 令和5年度 逸見賞（共著者）　　　　　　　　　　　　　　　
Inhibition of Morganella morganii growth and histamine production using a bacteriophage cocktail
山木将悟;山﨑浩司;川合祐史;坂之上葵;新井康介, Publisher, Japan

Aug. 2023, 日本食品科学工学会, Food Science and Technology Research Award for Best Paper (Vol.28) (共著者）　　　　　　　　　　　　　　　
Inhibition of Morganella morganii growth and histamine production using a bacteriophage cocktail
Shogo Yamaki;Aoi Sakanoue;Kosuke Arai;Koji Yamazaki;Yuji Kawai, Official journal, Japan

May 2022, 日本防菌防黴学会, 令和3年度 日本防菌防黴学会 論文賞（共著者）　　　　　　　　　　　　　　　
Spore heat resistance and growth ability at refrigeration temperatures of Bacillus spp. and Paenibacillus spp.
小林哲也;東孝憲;八十川大輔;山木将悟;山﨑浩司, Official journal, Japan

Sep. 2018, 日本食品微生物学会, 日本食品微生物学会 論文賞（責任著者）　　　　　　　　　　　　　　　
低温性ヒスタミン生成菌 Morganella psychrotoleransの水産食品における分布とヒスタミン生成能
加藤莉子;王迪;山木将悟;川合祐史;山崎浩司, Official journal

Aug. 2015, 日本食品科学工学会, 日本食品科学工学会誌 論文賞（責任著者）　　　　　　　　　　　　　　　
ナイシンによる水産練り製品における芽胞形成菌の発育制御
山崎浩司;田代卓;白浜慎也;全峻瑩;川合祐史

Aug. 2013, 日本食品科学工学会, 奨励賞　　　　　　　　　　　　　　　
蛍光 in situ ハイブリダイゼーション法を応用した迅速細菌検査法の開発と食品微生物制御
山崎浩司

Aug. 2012, 日本食品科学工学会, 日本食品科学工学会誌 論文賞（責任著者）　　　　　　　　　　　　　　　
培養併用蛍光 in situ ハイブリダイゼーション法を用いた汚染指標大腸菌の迅速定量検出
青井良平;清水茂雅;山崎浩司;澤辺智雄;川合祐史

May 2009, 日本食品化学会, 第４回論文賞（共著者）　　　　　　　　　　　　　　　
コールドチェーンの温度上昇を警告するインディケーターの開発
太田水生;山崎浩司;川合祐史;木暮秀則;二瀬克則;一色賢司

Nov. 1998, (社)日本缶詰協会, 平成10年度技術賞（責任著者）　　　　　　　　　　　　　　　
酸性飲料変敗菌 Alicyclobacillus acidoterrestris の耐熱性とその制御
山崎浩司;礒田千恵子;手塚裕和;川合祐史;信濃晴雄, Japan

Combination of a novel bacteriophage and d-serine effectively controls Vibrio parahaemolyticus growth in seafood
Daiki Miura, Shogo Yamaki, Itsuki Tabuchi, Yuji Kawai, Koji Yamazaki
Applied Food Research, 4, 2, 100558, 100558, Elsevier BV, Dec. 2024, [Peer-reviewed], [Last author], [International Magazine]
Scientific journal

Biological characterization and genomic analysis of a novel bacteriophage, MopsHU1, infecting Morganella psychrotolerans
Shogo Yamaki, Koji Yamazaki
Archives of Virology, 169, 9, 182, Springer Science and Business Media LLC, 17 Aug. 2024, [Peer-reviewed], [Last author], [International Magazine]
English, Scientific journal

Inhibition of Morganella morganii growth and histamine production using a bacteriophage cocktail
Shogo Yamaki, Aoi Sakanoue, Kosuke Arai, Koji Yamazaki, Yuji Kawai
Food Science and Technology Research, 28, 6, 489, 499, Japanese Society for Food Science and Technology, Nov. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal

Antimicrobial activity and mechanism of action of oregano essential oil against Morganella psychrotolerans and potential application in tuna
Di Wang, Chunsheng Li, Chuang Pan, Yueqi Wang, Huan Xiang, Yang Feng, Xianqing Yang, Shengjun Chen, Yongqiang Zhao, Yanyan Wu, Laihao Li, Yuji Kawai, Koji Yamazaki, Shogo Yamaki
LWT - Food Science and Technology, 165, 113758, 113758, Elsevier BV, Aug. 2022, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal

Broad host range bacteriophage, EscoHU1, infecting Escherichia coli O157:H7 and Salmonella enterica: Characterization, comparative genomics, and applications in food safety
Shogo Yamaki, Koji Yamazaki, Yuji Kawai
International Journal of Food Microbiology, 372, 109680, 109680, Elsevier BV, Jul. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal

Adsorption of Bacterial Spores on Surfaces of Polyethylene Terephthalate and Stainless Steel in Aqueous Solution
Tetsuya KOBAYASHI, Satoshi FUKUZAKI AND, Koji YAMAZAKI
日本防菌防黴学会誌, 50, 2, 49, 55, Feb. 2022, [Peer-reviewed], [Last author], [Domestic magazines]
Japanese, Scientific journal

Spore heat resistance and growth ability at refrigeration temperatures of Bacillus spp. and Paenibacillus spp.
Tetsuya Kobayashi, Takanori Azuma, Daisuke Yasokawa, Shogo Yamaki, Koji Yamazaki
Biocontrol Science, 26, 3, 147, 155, Sep. 2021, [Peer-reviewed], [Last author], [International Magazine]
English, Scientific journal, In this study, spore heat resistance and growth ability at refrigeration temperatures of Bacillus spp. and Paenibacillus spp. were determined. The spore D90°C of 67.6% (23 of 34 strains) of Bacillus and 73.9% (17 of 23 strains) of Paenibacillus was less than 15 min. The growth abilities of both genera were equivalent at 10°C. However, 71.1% (32 of 45 strains) of Paenibacillus and only 6.3% (3 of 48 strains) of Bacillus cereus group could grow at 4°C. Eight B. cereus strains formed spores with higher heat resistance compared to the other Bacillus strains assessed; however, they did not grow at tempreratures below 10°C. Conversely, four Paenibacillus strains formed spores with heat resistance equivalent to that of the eight B. cereus strains and grew at 6°C or lower. In particular, Paenibacillus sp. JCM13343 formed the highest heat-resistant spores (D90°C = 136.1 min) and grew well at 4°C. These results indicate that Paenibacillus can grow in processed foods during refrigerated storage and has the potential to cause spoilage as well as Bacillus. Therefore, Paenibacillus should be considered as one of the targets for microbiological control in refrigerated processed foods.

Long filamentous state of Listeria monocytogenes induced by sublethal sodium chloride stress poses risk of rapid increase in colony-forming units
Shogo Yamaki, Yuji Kawai, Koji Yamazaki
Food Control, 124, 107860, 107860, Elsevier BV, Jan. 2021, [Peer-reviewed], [Last author], [International Magazine]
English, Scientific journal

Development of a Novel Food Antimicrobial Technology: Application of Bacteriophages
Shogo Yamaki, Koji Yamazaki
Nippon Shokuhin Kagaku Kogaku Kaishi, 67, 10, 352, 359, Japanese Society for Food Science and Technology, 15 Oct. 2020, [Peer-reviewed], [Invited], [Last author, Corresponding author]
Japanese, Scientific journal

Sanitizing efficacy and antimicrobial mechanism of peracetic acid against histamine producing bacterium, Morganella psychrotolerans　　　　　　　　　　　　　　　
Wang, D., S. Yamaki, Y. Kawai, and K. Yamazaki
LWT-Food Science and Technology, 126, 109263, 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal

Histamine production behaviors of a psychrotolerant histamine-producer, Morganella psychrotolerans, in various environmental conditions　　　　　　　　　　　　　　　
Di Wang, Shogo Yamaki, Yuji Kawai, Koji Yamazaki
Current Microbiology, 77, 460, 467, 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal

Inhibitory effect of a combination with novel jumbo bacteriophages ΦMV-1 and ΦMV-4 on Morganella morganii subsp. morganii growth and histamine accumulation
Yamaki, S, S. Kuronuma, Y. Kawai, K. Yamazaki
International Journal of Food Microbiology, 317, 108457, 108457, Elsevier BV, 2020, [Peer-reviewed], [Last author], [International Magazine]
English, Scientific journal

Histamine Food Poisoning Associated with Fisheries Products and Histamine-Producing Bacteria　　　　　　　　　　　　　　　
Shogo Yamaki, Koji Yamazaki
日本食品微生物学会誌, 36, 2, 75, 83, 2019, [Peer-reviewed], [Invited], [Last author, Corresponding author]
Japanese, Scientific journal

Formation of Proton Motive Force Under Low-Aeration Alkaline Conditions in Alkaliphilic Bacteria
Toshihide Matsuno, Toshitaka Goto, Shinichi Ogami, Hajime Morimoto, Koji Yamazaki, Norio Inoue, Hidetoshi Matsuyama, Kazuaki Yoshimune, Isao Yumoto
Frontiers in Microbiology, 9, 2331, 2331, Frontiers Media SA, 02 Oct. 2018, [Peer-reviewed], [International Magazine]
English, Scientific journal, In Mitchell's chemiosmotic theory, a proton (H+) motive force across the membrane (Δp), generated by the respiratory chain, drives F1Fo-ATPase for ATP production in various organisms. The bulk-base chemiosmotic theory cannot account for ATP production in alkaliphilic bacteria. However, alkaliphiles thrive in environments with a H+ concentrations that are one-thousandth (ca. pH 10) the concentration required by neutralophiles. This situation is similar to the production of electricity by hydroelectric turbines under conditions of very limited water. Alkaliphiles manage their metabolism via various strategies involving the cell wall structure, solute transport systems and molecular mechanisms on the outer surface membrane. Our experimental results indicate that efficient ATP production in alkaliphilic Bacillus spp. is attributable to a high membrane electrical potential (ΔΨ) generated for an attractive force for H+ on the outer surface membrane. In addition, the enhanced F1Fo-ATPase driving force per H+ is derived from the high ΔΨ. However, it is difficult to explain the reasons for high ΔΨ formation based on the respiratory rate. The Donnan effect (which is observed when charged particles that are unable to pass through a semipermeable membrane create an uneven electrical charge) likely contributes to the formation of the high ΔΨ because the intracellular negative ion capacities of alkaliphiles are much higher than those of neutralophiles. There are several variations in the adaptation to alkaline environments by bacteria. However, it could be difficult to utilize high ΔΨ in the low aeration condition due to the low activity of respiration. To explain the efficient ATP production occurring in H+-less and air-limited environments in alkaliphilic bacteria, we propose a cytochrome c-associated "H+ capacitor mechanism" as an alkaline adaptation strategy. As an outer surface protein, cytochrome c-550 from Bacillus clarkii possesses an extra Asn-rich segment between the region anchored to the membrane and the main body of the cytochrome c. This structure may contribute to the formation of the proton-binding network to transfer H+ at the outer surface membrane in obligate alkaliphiles. The H+ capacitor mechanism is further enhanced under low-aeration conditions in both alkaliphilic Bacillus spp. and the Gram-negative alkaliphile Pseudomonas alcaliphila.

Antmicrobial and antibiofilm activity of sulfated polysaccharides from marine algae against dental plaque bacteria　　　　　　　　　　　　　　　
Joon-Young Jun, Min-Jeong Jung, In-Hak Jeong, Koji Yamazaki, Yuji Kawai, Byoung-Mok Kim
Marine Drugs, 16, 301, 313, Aug. 2018, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal

Biocontrol of Morganella morganii subsp. morganii and histamine accumulation on tuna meat by treatment with lytic bacteriophage
Yamaki, S, Kawai, Y, Yamazaki, K
Food Science and Technology Research, 24, 2, 329, 337, May 2018, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
English, Scientific journal

Distribution on Fishery Products and Histamine Producing Ability of Morganella psychrotolerans, a Psychrotrophic Histamine-Producing Bacterium
Kato Riko, Wang Di, Yamaki Shogo, Kawai Yuji, Yamazaki Koji
Japanese Journal of Food Microbiology, 34, 3, 158, 165, Japanese Society of Food Microbiology, Sep. 2017, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
Japanese, Scientific journal,

Morganella psychrotolerans is a novel psychrotrophic histamine producing bacterium and seems to cause histamine fish poisoning (scombroid poisoning). However, there is little information about the occurrence and histamine producing ability of this bacterium for food contamination. To elucidate the contamination status of M. psychrotolerans, we used an MPN-PCR method that can determine bacterial number more sensitive than a traditional plating method. Many kinds of fish samples purchased in Hokkaido and water samples collected in Hakodate area were used in this study. Eighty-five MPN-PCR positive samples were found in total 192 samples (44.3%) and thirty-seven strains of M. psychrotolerans were isolated from the positive samples. It suggests M. psychrotolerans is widely distributed in retail seafood product in Japan. Then the amounts of histamine produced by M. psychrotolerans isolates were investigated. All isolates produced more than 4,000 mg/L (4,000 ppm) of histamine after 48 h incubation at 25℃. Next, the growth and histamine production of M. psychrotolerans (JCM 16473^T, strain Mps. 3 from a horse mackerel sample) and Photobacterium phosphoreum NBRC 103031^T was compared in the liquid media containing 0.1 or 2.0% NaCl at 4℃. At 0.1% NaCl, histamine concentration produced by M. psychrotolerans was higher than that by P. phosphoreum. It indicates M. psychrotolerans will also become one of the important bacteria associated with histamine-poisoning at refrigeration temperature on seafood, as well as P. phosphoreum.

Suppression of Initial Adhesion and Biofilm Formation of Listeria monocytogenes by Nisin and Sucrose Fatty Acid Ester
Shogo Yamaki, Naho Hamada, Yuji Kawail, Koji Yamazaki
JOURNAL OF THE JAPANESE SOCIETY FOR FOOD SCIENCE AND TECHNOLOGY-NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI, 64, 10, 493, 501, JAPAN SOC FOOD SCIENCE TECHNOLOGY, 2017, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
Japanese, Scientific journal, Bacterial biofilms of foodborne pathogens pose the risk of secondary contamination in a food processing environment. Listeria monocytogenes is a Gram-positive, foodborne pathogen that contaminates various foods and environments. This bacterium can form biofilms on food-related surfaces. In this study, to inhibit biofilm formation by L. monocytogenes, we focused on suppressing the initial adhesion of the pathogen onto polystyrene dishes, which is the first step of biofilm formation. Screening of adhesion inhibitory materials using polystyrene dishes surface treated with food-related materials demonstrated high inhibitory effects of nisin and whey powder against L. monocytogenes adhesion. Moreover, surface treatment with nisin was able to delay biofilm formation of L. monocytogenes and the dish surface showed bactericidal activity. To improve the adhesion inhibitory effects of nisin, we combined nisin and a sucrose fatty acid ester, sucrose palmitate, for surface treatment, and this combination markedly improved the adhesion inhibitory effects. Thus, combined surface treatment with nisin and sucrose palmitate may be an effective method to prevent biofilm formation by L. monocytogenes in food processing environments.

Contribution of intracellular negative ion capacity to Donnan effect across the membrane in alkaliphilic Bacillus spp.
Toshitaka Goto, Toshinao Hirabayashi, Hajime Morimoto, Koji Yamazaki, Norio Inoue, Hidetoshi Matsuyama, Isao Yumoto
JOURNAL OF BIOENERGETICS AND BIOMEMBRANES, 48, 1, 87, 96, SPRINGER/PLENUM PUBLISHERS, Feb. 2016, [Peer-reviewed]
English, Scientific journal, To elucidate the energy production mechanism of alkaliphiles, the relationship between the H+ extrusion rate by the respiratory chain and the corresponding ATP synthesis rate was determined in the facultative alkaliphile Bacillus cohnii YN-2000 and compared with those in the obligate alkaliphile Bacillus clarkii DSM 8720(T) and the neutralophile Bacillus subtilis IAM 1026. Under high aeration condition, much higher ATP synthesis rates and larger Delta psi in the alkaliphilic Bacillus spp. grown at pH 10 than those in the neutralophilic B. subtilis grown at pH 7 were observed. This high ATP productivity could be attributed to the larger Delta psi in alkaliphiles than in B. subtilis because the H+ extrusion rate in alkaliphiles cannot account for the high ATP productivity. However, the large Delta psi in the alkaliphiles could not be explained only by the H+ translocation rate in the respiratory chain in alkaliphiles. There is a possibility that the Donnan effect across the membrane has the potential to contribute to the large Delta psi. To estimate the contribution of the Donnan effect to the large Delta psi in alkaliphilic Bacillus spp. grown at pH 10, intracellular negative ion capacity was examined. The intracellular negative ion capacities in alkaliphiles grown at pH 10 under high aeration condition corresponding to their intracellular pH (pH 8.1) were much higher than those in alkaliphiles grown under low aeration condition. A proportional relationship is revealed between the negative ion capacity and Delta psi in alkaliphiles grown under different aeration conditions. This relationship strongly suggests that the intracellular negative ion capacity contributes to the formation of Delta psi through the Donnan effect in alkaliphilic Bacillus spp. grown at pH 10.

マルチ蛍光スペクトル分析FISHFCシステム並びにそれを応用した衛生指標細菌迅速検査の開発　　　　　　　　　　　　　　　
大坪雅史, 清水健志, 須貝保徳, 高瀬雅由, 戸ケ崎恵一, 岡田迪德, 長尾直子, 山崎浩司
北海道工業技術センター研究報告, 14, 1, 11, 2016, [Last author]
Japanese

Combined Effect of Nisin and Commercial Pectin-hydrolysate Treatment on Survival and growth of Listeria monocytogenes in Soy-seasoned Salmon Roe Products
Shogo Yamaki, Shinya Shirahama, Tetsuya Kobayashi, Yuji Kawai, Koji Yamazaki
FOOD SCIENCE AND TECHNOLOGY RESEARCH, 21, 5, 751, 755, KARGER, Sep. 2015, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Soy-seasoned salmon roe products are commonly eaten in Japan; long-term preservation of these items requires refrigeration. However, salmon roe products are often contaminated with Listeria monocytogenes, which can potentially cause outbreaks of listeriosis. This study focused on developing a method to inhibit the growth of L. monocytogenes in salmon roe products by treating these foodstuffs with a combination of nisin and commercial pectin-hydrolysate, Neupectin L. We determined that treatment with 0.5 mg g(-1) nisin completely inhibited the growth of L. monocytogenes in raw salmon roe. However, treatment with nisin alone did not inhibit L. monocytogenes in soy-seasoned salmon roes. Further work showed that combined treatment with 0.5 mg g(-1) nisin and 0.5% Neupectin L completely inhibited the growth of L. monocytogenes during incubation at 12 degrees C. Therefore, this combination is an alternative way to control L. monocytogenes growth in salmon roe products.

Characterization of a novel bacteriophage, Phda1, infecting the histamine-producing Photobacterium damselae subsp damselae
S. Yamaki, Y. Kawai, K. Yamazaki
JOURNAL OF APPLIED MICROBIOLOGY, 118, 6, 1541, 1550, WILEY-BLACKWELL, Jun. 2015, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, AimsPhotobacterium damselae subsp. damselae is a potent histamine-producing micro-organism. The aim of this study was to isolate and characterize a bacteriophage Phda1 that infected P.damselae subsp. damselae to inhibit its growth and histamine accumulation.
Methods and ResultsPhda1 was isolated from a raw oyster, and the host range, morphology and the bacteriophage genome size were analysed. Phda1 formed a clear plaque only against P.damselae subsp. damselae JCM8969 among five Gram-positive and 32 Gram-negative bacterial strains tested. Phda1 belongs to the family Myoviridae, and its genome size was estimated as 352-395kb. According to the one-step growth curve analysis, the latent period, rise period and burst size of Phda1 were 60min, 50min and 19plaque-forming units per infected cell, respectively. Divalent cations, especially Ca2+ and Mg2+, strongly improved Phda1 adsorption to the host cells and its propagation. Phda1 treatment delayed the growth and histamine production of P.damselae subsp. damselae in an invitro challenge test.
ConclusionsThe bacteriophage Phda1 might serve as a potential antimicrobial agent to inhibit the histamine poisoning caused by P.damselae subsp. damselae.
Significance and Impact of the StudyThis is the first description of a bacteriophage specifically infecting P.damselae subsp. damselae and its potential applications. Bacteriophage therapy could prove useful in the prevention of histamine poisoning.

Isolation of antimicrobial agent from the marine algae Cystoseira hakodatensis
Joon-Young Jun, Sosuke Nakajima, Koji Yamazaki, Yuji Kawai, Hajime Yasui, Yasuyuki Konishi
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY, 50, 4, 871, 877, WILEY-BLACKWELL, Apr. 2015, [Peer-reviewed]
English, Scientific journal, Cystoseira hakodatensis is an unutilised brown algae belonging to family Sargassaceae. A crude methanol extract from the algae showed inhibitory effects on the growths of Bacillus cereus and Bacillus licheniformis. To isolate the major antimicrobial agent, a sequential active-guided isolation procedure was applied: liquid-liquid extraction, column chromatography and bio-autography. A marked antimicrobial agent (active ) was isolated in hydrophobic fraction and was determined to phenolics without carbohydrates and proteins by phytochemical test. Regarding the antimicrobial potential, the isolated active showed better inhibitory effects against B.cereus and B.licheniformis at 2 and 4 times of lower concentrations (62.5 and 31.3gmL(-1)) in comparison with epigallocatechin gallate. These results showed that C.hakodatensis is a potential source of antimicrobial agent capable of preventing the growth of the two bacteria.

Characterization of a novel Morganella morganii bacteriophage FSP1 isolated from river water
Shogo Yamaki, Takuo Omachi, Yuji Kawai, Koji Yamazaki
FEMS MICROBIOLOGY LETTERS, 359, 2, 166, 172, WILEY-BLACKWELL, Oct. 2014, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Morganella morganii has been identified as a causative agent of opportunistic infections and histamine poisoning. Bacteriophage is a virus and has recently been considered an alternative agent to antibiotics for the control of bacteria that have developed antibiotic resistance. In this study, a novel M.morganii bacteriophage isolated from river water was characterized. The isolated phage, termed FSP1, was purified by polyethylene glycol precipitation followed by cesium chloride density-gradient centrifugation. FSP1 has infectivity against only M.morganii and was identified as a Myoviridae bacteriophage through morphological analysis with transmission electron microscopy. According to the one-step growth curve, the FSP1 latent period, eclipse period, and burst size were 30, 20min, and 42PFU infected cell(-1), respectively. The genome size of FSP1 was estimated to be c. 45.6-49.4kb by restriction endonuclease analyses. Moreover, challenge testing against M.morganii in vitro revealed that FSP1 had high lytic activity and that the viable cell count of M.morganii was reduced by 6.12 log CFUmL(-1) after inoculation with FSP1 at a multiplicity of infection (MOI)=10. These results suggested that FSP1 could be used as a biocontrol agent against M.morganii for treatment of infectious disease treatment or food decontamination.

Development of a Rapid Enumeration Method Based on Fluorescence in situ Hybridization and the Control of Food-borne Pathogens
Koji Yamazaki
JOURNAL OF THE JAPANESE SOCIETY FOR FOOD SCIENCE AND TECHNOLOGY-NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI, 61, 7, 259, 267, JAPAN SOC FOOD SCIENCE TECHNOLOGY, 2014, [Peer-reviewed], [Invited], [Lead author, Corresponding author]
Japanese, Scientific journal, Conventional plate counting with selective agars is time-consuming and labor intensive for the detection and enumeration a microorganisms associated with food-borne illnesses from food and environmental samples. In addition, it may be unsuitable for the rapid estimations required for food sanitation and hygiene. To overcome these technical challenges, a superior method, termed FISHFC (fluorescence in situ hybridization [FISH] in combination with filter cultivation [FC] on a membrane filter), was developed. The FISHFC method has equal detection accuracy to the conventional plate counting method. It enumerates only viable food-borne pathogens from food samples within 8-17 h, which suggests that the accurate evaluation of pathogen contamination can be completed within two working days. Therefore, the FISHFC method with species-specific detection probes contributes to ensuring food safety. This article introduces the rapid enumeration FISHFC method for the estimation of food-borne pathogens.

Growth Inhibition of Spore-forming Bacteria in Fish-paste Products by Nisin
Koji Yamazaki, Taku Tashiro, Shinya Shirahama, Joon-young Jun, Yuji Kawai
JOURNAL OF THE JAPANESE SOCIETY FOR FOOD SCIENCE AND TECHNOLOGY-NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI, 61, 2, 70, 76, JAPAN SOC FOOD SCIENCE TECHNOLOGY, 2014, [Peer-reviewed], [Lead author, Corresponding author]
Japanese, Scientific journal, We investigated the effect of nisin and sucrose fatty acid esters on the growth of spoilage bacteria in fish-paste products. Nisin showed antibacterial activity against Bacillus subtilis and B. licheniformis vegetative cells and spores in liquid medium. Also, nisin exhibited a synergistic effect in combination with sucrose fatty acid esters (sucrose monolaurate and sucrose monopalmitate). The addition of nisin (12.5 mu g/g) to fish-paste products suppressed the growth of B. subtilis and B. licheniformis during storage at 20 degrees C and resulted in longer shelf-life of fish-paste products compared to control and fish-paste products with added potassium sorbate. In addition, the growth of spoilage bacteria was strongly inhibited by the combination of nisin (12.5 mu g/g) and sucrose fatty acid esters (10 mg/g) in fish-paste products without starch. From these findings, we conclude that the addition of nisin is a potential alternative method for preventing spoilage caused by spore-forming bacteria in fish-paste products.

Current trends in risk management research for ensuring food safety throughout seafood production, processing and distribution
Tomoo Sawabe, Masataka Satomi, Koji Yamazaki
Nippon Suisan Gakkaishi (Japanese Edition), 80, 6, 1002, Nihon Suisan Gakkai, 2014
Japanese, Scientific journal

Rapid Quantitative Detection of Salmonella enterica Using Fluorescence In Situ Hybridization with Filter-cultivation (FISHFC) Method
Shigemasa Shimizu, Ryouhei Aoi, Yui Osanai, Yuji Kawai, Koji Yamazaki
FOOD SCIENCE AND TECHNOLOGY RESEARCH, 19, 1, 59, 67, KARGER, Jan. 2013, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Specific detection and enumeration of Salmonella enterica in food using conventional culture-based methods (CCBM) are time consuming and labor intensive. This study was conducted to develop a rapid S. enterica detection and enumeration method by combining fluorescence in situ hybridization (FISH) with micro-colony formation culture (FISHFC). Specificity tests of the SAL343 probe for S. enterica detection revealed that SAL343-associated fluorescent micro-colonies were observed specifically for S. enterica, but not for any other organisms. This finding suggests that SAL343 is highly specific for detecting S. enterica using FISHFC. For validation, FISHFC with SAL343 was compared to CCBM, with multiple selective agar, using spiked food samples; no significant differences in enumeration were found between FISHFC and CCBM (p > 0.05). The FISHFC method allowed enumeration of S. enterica within 10 h while CCBM allowed enumeration within 5 days. Therefore, the FISHFC method has potential application for more rapid and specific enumeration of S. enterica in food samples compared to other available methods.

Rapid Detection of Staphylococcus aureus Using Fluorescence in situ Hybridization with Filter-Cultivation (FISHFC) Method
SHIMIZU Shigemasa, KUBOSAWA Yosuke, MATSUURA Misato, KAWAI Yuji, YAMAZAKI Koji
Japanese journal of food microbiology, 28, 1, 29, 36, 日本食品微生物学会, 31 Mar. 2011, [Peer-reviewed], [Last author, Corresponding author]
Japanese, Scientific journal

Rapid Quantification of Escherichia coli as an Indicator of Food Contamination Using Fluorescence in situ Hybridization with Filter Cultivation (FISHFC)
Ryohei Aoi, Shigemasa Shimizu, Koji Yamazaki, Tomoo Sawabe, Yuji Kawai
JOURNAL OF THE JAPANESE SOCIETY FOR FOOD SCIENCE AND TECHNOLOGY-NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI, 58, 10, 483, 489, JAPAN SOC FOOD SCIENCE TECHNOLOGY, 2011, [Peer-reviewed], [Corresponding author]
Japanese, Scientific journal, Conventional plate counting for Escherichia coli is time consuming, and more rapid and specific quantification methods are desired. The fluorescence in situ hybridization with filter cultivation (FISHFC) method has already been developed to specifically detect viable microorganisms such as Listeria monocytogenes, Clostridium perfringens and Staphylococcus aureus. The purpose of this study was to develop and estimate the accuracy of the FISHFC method for E. coli detection in food samples. An Alexa Fluor (R) 647-labeled oligonucleotide probe. ECO636. targeting a species-specific sequence of E. coli 16SrRNA was designed. ECO636-conferred fluorescence was observed for E coli and Shigella spp. micro-colonies, but not for any other organisms. This suggests that the ECO636 probe is highly specific for E. coli and Shigella spp. This assay using the FISHFC method can be completed within 9 hours, including a 7-hour cultivation period, and is much faster compared to standard plating methods, which require more than 4 days, for the confirmation of E. coli. Viable E. coli counts in food samples determined by the FISHFC method were not significantly different to those obtained by the conventional plate counting method p > 0.051 These results suggest that the proposed FISHFC method is more rapid than and equally as reliable as the standard methods used for estimating viable E. coli numbers as indicators of food contamination in food.

Microbiota during fermentation of chum salmon (Oncorhynchus keta) sauce mash inoculated with halotolerant microbial starters: Analyses using the plate count method and PCR-denaturing gradient gel electrophoresis (DGGE)
Shuji Yoshikawa, Daisuke Yasokawa, Koji Nagashima, Koji Yamazaki, Hideyuki Kurihara, Tomoki Ohta, Yuji Kawai
FOOD MICROBIOLOGY, 27, 4, 509, 514, ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, Jun. 2010, [Peer-reviewed]
English, Scientific journal, Nine different combinations of mugi koji (barley steamed and molded with Aspergillus oryzae) and halotolerant microorganisms (HTMs), Zygosaccharomyces rouxii, Candida versa fills, and Tetragenococcus halophilus, were inoculated into chum salmon sauce mash under a non-aseptic condition used in industrial fish sauce production and fermented at 35 +/- 2.5 degrees C for 84 days to elucidate the microbial dynamics (i.e., microbial count and microbiota) during fermentation. The viable count of halotolerant yeast (HTY) in fermented chum salmon sauce (FCSS) mash showed various time courses dependent on the combination of the starter microorganisms. Halotolerant lactic acid bacteria (HTL) were detected morphologically and physiologically only from FCSS mash inoculated with T halophilus alone or with T halophilus and C. versatilis during the first 28 days of fermentation. Only four fungal species, Z. rouxii, C versatilis, Pichia guilliermondii, and A. oryzae, were detected throughout the fermentation by PCR-denaturing gradient gel electrophoresis (PCR-DGGE). In FCSS mash, dominant HTMs, especially eumycetes, were nonexistent. However, under the non-aseptic conditions, undesirable wild yeast such as P. guilliermondii grew fortuitously. Therefore, HTY inoculation into FCSS mash at the beginning of fermentation is effective in preventing the growth of wild yeast and the resultant unfavorable flavor. (C) 2009 Elsevier Ltd. All rights reserved.

Effect of Halotolerant Starter Microorganisms on Chemical Characteristics of Fermented Chum Salmon (Oncorhynchus keta) Sauce
Shuji Yoshikawa, Hideyuki Kurihara, Yuji Kawai, Koji Yamazaki, Akira Tanaka, Takafumi Nishikiori, Tomoki Ohta
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 58, 10, 6410, 6417, AMER CHEMICAL SOC, May 2010, [Peer-reviewed]
English, Scientific journal, Chum salmon sauce mash was inoculated with barley koji (barley steamed and molded with Aspergillus oryzae) and halotolerant microorganisms (HTMs), Zygosaccharomyces rouxii, Candida versatilis, and Tetragenococcus halophilus, in nine different combinations under non-aseptic conditions similar to the industrial fish sauce production and fermented at 35 +/- 2.5 degrees C for 84 days. The changes in the chemical components, color, and sensory properties during fermentation were investigated. Free amino acid content was increased, and the browning of fish sauce was enhanced by the usage of barley koji during fermentation. The halotolerant yeast (HTY) produced ethanol and repressed the browning by consumption of reducing sugar. Inoculated Z. rouxii in the fish sauce mash produced 2-phenylethanol (2-PE) and 4-hydoxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF), and C. versatilis in the fish sauce mash produced 4-ethylguaiacol (4-EG), known as characteristic flavor compounds in soy sauce, adding soy-sauce-like flavor to the fish sauce. Thus, inoculation of HTMs and barley koji was effective for conferring the soy-sauce-like flavor and increasing free amino acid and ethanol contents in fish sauce product.

Assessing and enhancing the antimicrobial effect of nisin in soy-seasoned salmon Oncorynchus keta roe using a Pediococcus pentosaceus fermentate and pectin
Dominic Kasujja Bagenda, Koji Yamazaki, Tetsuya Kobayashi, Yuji Kawai
FISHERIES SCIENCE, 76, 2, 395, 401, SPRINGER TOKYO, Mar. 2010, [Peer-reviewed]
English, Scientific journal, The compatibility and potential of nisin, a Pediococcus pentosaceus fermentate, and pectin to inhibit Listeria monocytogenes in soy-seasoned salmon roe at 5 and 12 degrees C was studied. The compatibility of nisin and soy-seasoning was assessed by adding 6.3 mu g/g of nisin to freshly washed or soy-seasoned (60% soy, 15% sweet-sake, 5% sugar, and 15% water) roe and monitoring the growth of an inoculum of L. monocytogenes (5.6 Log CFU/g; strains IID 578, IID 581, ATCC 7644) as well as residual nisin concentrations at 12 degrees C. The combined antimicrobial potential was determined by monitoring growth of the inoculum (5.2 Log CFU/g) in roe when the soy-seasoning contained nisin (0.05 g/ml), fermentate powder made by freeze-drying a broth culture of P. pentosaceus (0.1 g/ml), and 2% pectin at 5 or 12 degrees C. Chloride content, total acid content, and the effect of pectin on acceptability of roe were also determined. Nisin was more effective in soy-seasoned roe than in freshly washed roe. Microbial growth was completely inhibited by a combination of soy-seasoning, nisin, the fermentate, and pectin. Despite its viscosity, pectin did not significantly affect the chemical properties or acceptability of roe relative to pectin-free roe samples (P < 0.05). Based on these results, we conclude that nisin's potential as an antimicrobial agent in soy-seasoned roe can be enhanced using fermentates and pectin.

Influence of medium components and growth conditions on Pediocin Iz.3.13 production by Pediococcus pentosaceus Iz.3.13, isolated from Japanese traditional fermented seafood
Kobayashi, T, K.Yamazaki, D.K. Bagenda, Y. Kawai
Bull. Fish. Sci. Hokkaido Univ, 60, 1, 5, 12, 北海道大学大学院水産科学研究院 = Research Faculty of Fisheries Sciences, Hokkaido University, 2010, [Corresponding author]
English, Scientific journal, Growth requirements for maximum production of pediocin Iz3.13 by Pediococcus pentosaceus Iz3.13 were studied. Physical and chemical parameters that enhanced pediocin production included incubation in static broth at 30℃, with an initial pH of 4.5. Optimum nutritional conditions that enhanced pediocin Iz3.13 production were 3.5% Trypticase peptone, 3.5% Phytone peptone or 5.0% Proteose peptone No.3 as nitrogen sources, and glucose or maltose as carbon sources. Supplementing growth media with beef extract and MgCl2 also enhanced production. This study proposes an optimized growth medium containing 5.0% Proteose peptone No.3, 3.5% Phytone peptone, 2.5% glucose, 1.5% MgCl2, 3.0% beef extract and 0.25% K2HPO4. This medium significantly enhanced pediocin Iz3.13 production (5.1 fold increase) as compared to a basal medium.

Comparison and improvement of detection media for sub-lethal injured Clostridium perfringens
Shimizu Shigemasa, Horiguchi Asuka, Yamazaki Koji, Kawai Yuji
Bulletin of fisheries sciences, Hokkaido University, 59, 2, 37, 42, Research Faculty of Fisheries Sciences, Hokkaido University, Aug. 2009, [Corresponding author]
Japanese, Clostridium perfringens（ウェルシュ菌）は芽胞形成グラム陽性の偏性嫌気性細菌であり、土壌、河川などの自然界や人、動物の腸管などに広く常在する細菌である。本菌の中にはエンテロトキシンを産生するものが存在し、そのような毒素産生株に汚染された食品を摂取することで食中毒が発生する。食品や環境からC. perfringensを分離する方法はこれまで多数報告されており、そのいくつかは公定法または標準法として採用されている。我が国における食品からのC. perfringens の検出には、3種類の培地、すなわちカナマイシン含有卵黄加CW寒天培地、Tryptose sulfite cycloserine（TSC）寒天培地およびハンドフォード改良寒天培地が食品衛生検査指針（2003）で推奨されており、その中でもカナマイシン含有卵黄加CW寒天培地が平板塗抹法による生菌数測定を行う際に良く利用されている。一方、海外ではTSC寒天培地を推奨している場合が多い。これらの培地は、比較的類似した成分を基礎成分としているが、選択剤として含有する抗生物質の種類と濃度に大きな差異がある。本研究では、我が国でC. perfringens の検出に頻繁に用いられている選択培地での加熱損傷C. perfringens の検出感度および損傷回復剤の効果について検討した。

Fluorescent in situ hybridization in combination with filter cultivation (FISHFC) method for specific detection and enumeration of viable Clostridium perfringens
S. Shimizu, M. Ootsubo, Y. Kubosawa, I. Fuchizawa, Y. Kawai, K. Yamazaki
FOOD MICROBIOLOGY, 26, 4, 425, 431, ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, Jun. 2009, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, To reduce time for enumeration of viable Clostridium perfringens fluorescence in situ hybridization in combination with filter Cultivation (FISHFC) was employed. The method utilized a CLP-180 probe, based on the 16S rRNA region of C. perfringens, and FISHFC fluorescence microscopy to detect C. perfringens, but not organisms from other species. Optimal Cultivation requirements for micro-colony formation were TSC medium, anaerobic conditions, 37 degrees C, and incubation for 6 h. Under these conditions, micro-colony diameters reached 100 full, a size sufficient for hybridization. Enumeration Of C. perfringens using the CLP-180-aided FISHFC method was realized in 9 h as compared to 3-5 days required by the conventional plate count method. Moreover, viable C. perfringens counts of food samples from the two methods were not significantly different.
It was concluded that the CLP-180-aided FISHFC is faster than conventional plate Count methods and equally accurate (detection limit: 2 log CFU/g). The CLP-180-aided FISHFC method for rapidly evaluating C. perfringens in food samples, can contribute to ensuring food safety. (c) 2009 Elsevier Ltd. All rights reserved.

A novel membrane-anchored cytochrome c-550 of alkaliphilic Bacillus clarkii K24-1U: expression, molecular features and properties of redox potential
Ogami, Shinichi, Hijikata, Shoichi, Tsukahara, Tamotsu, Mie, Yasuhiro, Matsuno, Toshihide, Morita, Naoki, Hara, Isao, Yamazaki, Koji, Inoue, Norio, Yokota, Atsushi, Hoshino, Tamotsu, Yoshimune, Kazuaki, Yumoto, Isao
EXTREMOPHILES, 13, 3, 491, 504, SPRINGER JAPAN KK, May 2009, [Peer-reviewed]
English, Scientific journal, A membrane-anchored cytochrome c-550, which is highly expressed in obligately alkaliphilic Bacillus clarkii K24-1U, was purified and characterized. The protein contained a conspicuous sequence of Gly(22)-Asn(34), in comparison with the other Bacillus small cytochromes c. Analytical data indicated that the original and lipase-treated intermediate forms of cytochrome c-550 bind to fatty acids of C-15, C-16 and C-17 chain lengths and C-15 chain length, respectively, and it was considered that these fatty acids are bound to glycerol-Cys(18). Since there was a possibility that the presence of a diacylglycerol anchor contributed to the formation of dimeric states of this protein (20 and 17 kDa in SDS-PAGE), a C18M (Cys(18) -> Met)-cytochrome c-550 was constructed. The molecular mass of the C18M-cytochrome c-550 was determined as 15 and 10 kDa in SDS-PAGE and 23 kDa in blue native PAGE. The C18M-cytochrome c-550 bound with or without Triton X-100 formed a tetramer as the original cytochrome c-550 bound with Triton X-100, as determined by gel filtration. The midpoint redox potential of cytochrome c-550 as determined by redox titration was +83 mV, while that determined by cyclic voltammetric measurement was +7 mV. The above results indicate that cytochrome c-550 is a novel cytochrome c.

Multi-Probe-Fluorescence in situ Hybridization for the Rapid Enumeration of Viable Vibrio parahaemolyticus
Tomoo Sawabe, Ai Yoshizawa, Yuko Kawanishi, Eriko Komatsu-Takeda, Satoshi Nakagawa, Toko Sawabe, Masashi Ootubo, Masataka Satomi, Yutaka Yano, Koji Yamazaki
MICROBES AND ENVIRONMENTS, 24, 3, 259, 264, JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE, 2009, [Peer-reviewed]
English, Scientific journal, A one-step multi-probe FISH method of detecting viable Vibrio parahaemolyticus was developed. Three candidate regions, corresponding to Helix 440+441, Helix 588, and Helix 1241 in 16S rRNA, were selected for detection, the thermodynamic parameters (Delta G(overall)) of the probes were optimized, and VP437, VP612 and VP1253, whose fluorescence were 1.7 to 11.3 times that of Delta G(overall)-unadjusted sequences, were designed. The addition of competitive oligo-nucleotides to reactions with VP612 and VP1253 strengthened the specificity of the probes. The three probes were labeled with FITC, TAMRA, and Cy5, respectively, and using a mixture of the probes and six competitive oligo-nucleotides, one-step FISH was applied to the species-specific detection of V. parahaemolyticus including epidemic strains of O3:K6 and O4:K68 serotypes. V. alginolyticus, V. rotiferianus, and V. campbellii were not detected in the reaction. Microcolonies (30-80 mu m in diameter) of V. parahaemolyticus were observed within 6 hours at 37 degrees C on seawater agar plates in both fresh and heat-damaged V. parahaemolyticus. Viable bacterial counts based on the proposed method were significantly different from those measured with typical vibrio selective media (CHROMagar Vibrio and TCBS).

Specific and Rapid Quantification of Viable Listeria monocytogenes Using Fluorescence in situ Hybridization in Combination with Filter Cultivation
Ikufumi Fuchizawa, Shigemasa Shimizu, Masashi Ootsubo, Yuji Kawai, Koji Yamazaki
MICROBES AND ENVIRONMENTS, 24, 3, 273, 275, JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE, 2009, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, We developed a new method that rapidly and specifically enumerates only viable Listeria monocytogenes in food using fluorescence in situ hybridization in combination with filter cultivation (FISHFC). Viable L. monocytogenes could be specifically quantified within 16 h using an Alexa647-labeled mRL-2 probe. The coefficient of the correlation between the new method and the conventional plating method was 0.959.

Specific detection and quantitative enumeration of Listeria spp. using fluorescent in situ hybridization in combination with filter cultivation (FISHFC)
I. Fuchizawa, S. Shimizu, Y. Kawai, K. Yamazaki
JOURNAL OF APPLIED MICROBIOLOGY, 105, 2, 502, 509, WILEY-BLACKWELL, Aug. 2008, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Aims: To design a rapid specific method for enumeration of viable Listeria spp. using the fluorescence in situ hybridization with filter cultivation (FISHFC) method.
Methods and Results: The probe, Lis-1400, was designed from the 23S rRNA region of the Listeria genome, and labelled with 5'-carboxy-tetramethyl-rhodamine-N- hydroxy-succinimide-ester. Fluorescence was observed for all Listeria species but not for any organisms from the other genera, suggesting Lis-1400 is highly specific for Listeria spp. For purposes of filter cultivation prior to hybridization, hydrophilic polypropylene membrane filters gave better contrast between fluorescing colonies and background fluorescence. This was because of a high S/N ratio (fluorescence intensity of each microcolony/fluorescence intensity of background noise) after FISH treatment. Results were achievable in 14 h using Lis-1400-aided FISHFC as compared with 4-7 days required for confirmation of Listeria spp. by conventional plate count methods. Moreover, viable Listeria counts in selected food samples showed no significant differences between Lis-1400-aided FISHFC and conventional methods.
Conclusions: The Lis-1400-aided FISHFC method is more efficient than conventional methods for enumeration of viable Listeria spp. in food samples.
Significance and Impact of the Study: For enumeration of Listeria spp., Lis-1400-aided FISHFC method is equally accurate yet faster than conventional plate count methods, and can be valuable in the control of listeriosis.

Characterization of an antibacterial substance produced by Pediococcus pentosaceus Iz3.13 isolated from Japanese fermented marine food
Dominic K. Bagenda, Kentaro Hayashi, Koji Yamazaki, Yuji Kawai
FISHERIES SCIENCE, 74, 2, 439, 448, SPRINGER JAPAN KK, Apr. 2008, [Peer-reviewed]
English, Scientific journal, Fermentation of raw marine food is popular in Japan, but is occasionally associated with Clostridium botulinum outbreaks. Lactic acid bacteria in fermented food produce antibacterial substances (ABS). An ABS producing strain Iz.3.13 was isolated from commercially fermented 'izushi'. The purpose of this study was to characterize strain Iz.3.13 and the ABS it produced. Strain Iz.3.13 was identified as Pediococcus pentosaceus by morphological, biochemical characteristics and 16S rDNA sequence similarity. Strain Iz.3.13ABS produced and ABS inhibited Listeria and Cl. botulinum. The ABS was inhibited by alpha-chymotrypsin and proteinase K, but not by catalase, lipase, or alpha-amylase indicating the ABS was a bacteriocin. The bacteriocin remained active at 100 degrees C for 15 min, and pH 2-8. Mode of action of the bacteriocin against Listeria monocytogenes was bactericidal and bacteriolytic. Partial analysis of the purified bacteriocin by Edman degradation, showed a 22-amino acid residue closely related to Pediocin AcH. However, MALDI-TOF-MS analysis estimated a molecular mass of 4621.6 Da. This is a first report of a Cl. botulinum-inhibiting bacteriocin-producer from traditional Japanese fermented marine food. The bacteriocin produced by Ped. pentosaceus Iz.3.13 might have potential to ensure the safety of fermented marine food.

Development of the indicator to warn deviant temperature raise in cold chain
OTA MIZUKI, YAMAZAKI KOJI, KAWAI YUJI, KOGURE HIDENORI, FUTASE KATSUNORI, ISSHIKI KENJI
日本食品化学学会誌, 15, 1, 18, 22, Japanese Society of Food Chemistry, Apr. 2008, [Peer-reviewed]
Japanese, Scientific journal, The purpose of this study was to develop low cost color indicators of temperature abuse in the cold chain. To develop the indicators, bacterial strain sk22 isolated from commercial cod was used. Strain sk22 can grow and produce acid from carbohydrate at 4℃. Incubating sk22 in modified Oxidation- Fermentation broth at 12℃ (with initial inoculums levels of 10⁶ and 10³ CFU/ml) resulted in color changes of 35 and 72 hours respectively. Further, addition of buffer delayed color changes. Therefore by adjusting inoculum levels and/or buffer concentration, timing of color change could be controlled. To make the indicator safe for food use, the suitability of nine pigments and food grade buffers was tested to judge their effects on the color change. Red cabbage pigment was the most suitable one of the tested pigments because color change was clear. Furthermore, addition of food grade ammonium sulfate as a buffer enhanced clarity of color change.

Effect of exogenous methyl jasmonate on lipoxygenase activity in a red alga Porphyra yezoensis　　　　　　　　　　　　　　　
Kawai Y, Narita K, Yamazaki K, Kato K, Suzuki T, Mikami K, Saga N
Proceedings of 5th World Fisheries Congress (CD-ROM), 3f20, 2008
English, International conference proceedings

Cytochrome c-552 from gram-negative alkaliphilic Pseudomonas alcaliphila AL15-21(T) alters the redox properties at high pH
Toshihide Matsuno, Nozomu Morishita, Koji Yamazaki, Norio Inoue, Yukari Sato, Nobutoshi Ichise, Isao Hara, Tamotsu Hoshino, Hidetoshi Matsuyama, Kazuaki Yoshimune, Isao Yumoto
JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 103, 3, 247, 254, SOC BIOSCIENCE BIOENGINEERING JAPAN, Mar. 2007, [Peer-reviewed]
English, Scientific journal, A soluble class I cytochrome c of an alkaliphile was purified and characterized, and its primary structure was determined. This is the first example of a soluble class I cytochrome c in alkaliphiles. Cells the alkaliphilic gram-negative bacterium Pseudomonas alcaliphila AL15-21(T) grown at pH 10 had a soluble cytochrome c content that was more than twofold that of strain AL15-21(T) cells grown at pH 7 under air-limited conditions. Cytochrome c-552, a soluble cytochrome c with a low molecular weight, was purified from strain AL15-21(T) cells grown at pH 10 under air-limited conditions. Cytochrome c-552 had a molecular mass of 7.5 kDa and exhibited an almost fully reduced state in the resting form, which exhibited absorption maxima at wavelengths of 552, 523 and 417 nm. In the oxidized state, it exhibited an absorption maximum at 412 nm when it was oxidized by ferricyanide, its isoelectric point (pl) was 4.3 and it contained one heme c as a prosthetic group. Cytochrome c-552 was autoreduced at pH 10, and the autoreduction was reproducible. On the other hand, the autoreduction of cytochrome c-552 was not observed at pH 7.0. When pH was increased from 7.0 to 8.3, its midpoint redox potentials (E-m values) increased from +228 mV to +276 mV as determined by redox titrations, and from +217 mV to +275 mV as determined by cyclic voltammetric measurements. The amino acid sequence deduced by cytochrome c-552 gene analysis revealed that the sequence consists of 96 residues, including 19 residues as an amino-terminal signal peptide. A phylogenetic tree based on amino acid sequence indicated that the protein belongs to group 4, cytochrome c(5) in class I cytochrome c.

Inhibition of Listeria monocytogenes by freeze-dried piscicocin CS526 fermentate in food
T. Azuma, D. K. Bagenda, T. Yamamoto, Y. Kawai, K. Yamazaki
LETTERS IN APPLIED MICROBIOLOGY, 44, 2, 138, 144, BLACKWELL PUBLISHING, Feb. 2007, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Aims: The effectiveness of freeze-dried powder, fermented with bacteriocin producing Carnobacterium piscicola CS526, was evaluated for the inhibition of Listeria monocytogenes in a food model.
Methods and Resutls: A 10% solution of milk whey powder was fermented with a bacteriocinogenic C. piscicola CS526 Bac(+) or its nonbacteriocinogenic mutant strain CS526 Bac(-) at 30 degrees C for 12 h and freeze-dried. The freeze-dried piscicocin CS526 Bac(+) fermentate exhibited strong anti-listerial activity even at a concentration of 1% (w/v) in sterile water (pH 7), but the piscicocin CS526 Bac(-) fermentate and nonfermented whey powder had no anti-listerial activity. In the presence of 10% piscicocin CS526 Bac(+) fermentate, L. monocytogenes in ground meat rapidly decreased from 10(5) CFU g(-1) to less than the detection limit (3.0 x 10(3) CFU g(-1)) within 5 and 1 days at 4 and 12 degrees C, and was bacteriostatically inhibited for 25 and 4 days at 4 and 12 degrees C respectively. Furthermore, this inhibitory effect was enhanced at lower temperatures.
Conclusions: Piscicocin CS526 Bac(+) fermentate was effective for the control of L. monocytogenes in a food model at refrigeration temperatures.
Significance and Impact on the Study: A freeze-dried bioactive piscicocin CS526 Bac(+) powder can be a powerful tool to ensure food safety against L. monocytogenes contamination in refrigerated foods such as ready-to-eat products.

Effect of treatment with electrolyzed NaCl solutions and essential oil compounds on the proximate composition, amino acid and fatty acid composition of carp fillets
Barakat S. M. Mahmoud, Y. Kawai, K. Yamazaki, K. Miyashita, T. Suzuki
FOOD CHEMISTRY, 101, 4, 1492, 1498, ELSEVIER SCI LTD, 2007, [Peer-reviewed]
English, Scientific journal, This investigation was undertaken to evaluate the effect of treatment with electrolyzed NaCl solutions and 1% essential oil (0.5% carvacrol + 0.5% thymol) on the proximate composition and nutritional components (amino acids and fatty acids) of carp fillets at room temperature (25 degrees C). Carp fillet samples were treated with anodic electrolyzed NaCl solution [EW (+)], cathodic electrolyzed NaCl solution [EW (-)] followed by EW (+) [EW (-)/EW (+)], 1% essential oil (0.5% carvacrol + 0.5% thymol) [1% (Cv + Ty)], EW (+) followed by 1% (Cv + Ty) [EW (+)/1% (Cv + Ty)] and EW (-) followed by EW (+) and finally with 1% (Cv + Ty) [EW (-)/EW (+)/I% (Cv + Ty)]. Proximate composition, SDS-PAGE, amino acid composition, digestibility and fatty acid composition were used to determine the changes in carp fillet composition. Moisture, total lipid, total protein, ash and carbohydrate contents of the carp fillets were approximately 76%, 3.9%, 17.5%, 1.0% and 0.40%, respectively. The dominant amino acid was glutamic acid, and the composition ranged from 14.2 to 14.5 mol%. Protein digestibility of the carp fillets was approximately 85%. Oleic acid was the major monounsaturated acid in the carp fillets (41.0-41.9%). These results show that our method of fish preservation, using electrolyzed NaCl solutions and 1% (Cv + Ty), did not affect the quality (nutritional components) of carp fillets, and could be a good alternative to synthetic preservatives routinely used in the food industry. (c) 2006 Elsevier Ltd. All rights reserved.

Application of Bacteriocins in Food Preservation and Safety　　　　　　　　　　　　　　　
Dominic K. Bagenda, Koji Yamazaki
Food, 1, 2, 137, 148, 2007, [Peer-reviewed], [Invited], [Last author, Corresponding author]
English, Scientific journal

beta-Glucosidase inhibitory activities of phenylpropanoid glycosides, vanicoside A and B from Polygonum sachalinense rhizome
Y. Kawai, H. Kumagai, H. Kurihara, K. Yamazaki, R. Sawano, N. Inoue
FITOTERAPIA, 77, 6, 456, 459, ELSEVIER SCIENCE BV, Sep. 2006, [Peer-reviewed]
English, Scientific journal, The phenylpropanoid glycosides, vanicoside A and B, isolated from rhizomes of giant knotweed (Polygonum sachalinense) showed p-glucosidase inhibitory activity, with IC50 values of 59.8 and 48.3 mu g/ml (59.9 and 50.5 mu M), respectively. In contrast, p-coumaric acid and ferulic acid, corresponding to phenylpropanoyl moieties of vanicosides, exhibited very little inhibition. (c) 2006 Elsevier B.V. All rights reserved.

Preservative effect of combined treatment with electrolyzed NaCl solutions and essential oil compounds on carp fillets during convectional air-drying
BSM Mahmoud, K Yamazaki, K Miyashita, Y Kawai, IS Shin, T Suzuki
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY, 106, 3, 331, 337, ELSEVIER SCIENCE BV, Feb. 2006, [Peer-reviewed]
English, Scientific journal, The antimicrobial and antioxidant effects on carp fillet samples of treatments with alkaline electrolyzed NaCl solution EW (-) prior to treatment with acidic electrolyzed NaCl solution EW (+) and 1% solutions of the essential oils consisting of 0.5% carvacrol and 0.5% thymol (1% Cv+Ty) were tested. First carp fillet samples were treated with EW (-), then EW (+), followed by 1% (C+T), represented as [EW (-)/EW (+) / 1% (Cv+Ty)] for 15 min, during drying at 45 degrees C. Samples were subsequently evaluated by microbiological, chemical and sensory analyses. Microbiological analyses indicated that the initial total microbial counts of samples treated with EW (-)/EW (+), 1% (Cv+Ty) or EW (-)/EW (+)/1% (Cv+Ty) were significantly (p < 0.05) reduced, compared with the control sample. Treatment with EW (-)/EW (+)/1% (Cv+Ty) gave the strongest overall inhibition of microbial growth when compared to all of the other treatments. The volatile basic nitrogen (VBN) value of samples treated with EW (-)/EW (+)1% (Cv+Ty) was kept at low level (18.46 +/- 0.45) until the end of drying period (5 days), compared with control samples (40.33 +/- 0.58). Treatment with EW (-)/EW (+)/1% (Cv+Ty) during drying significantly reduced the peroxide values (PV) and thiobarbituric acid values (TBA). Sensory evaluation indicated that there were significant differences (p < 0.05) in the color, odor, taste, flavor and texture, on the end of the 5-day drying period between samples treated with EW (-)/EW (+)/1% (Cv+Ty), as compared to all of the other treatments. We conclude that treatment with EW (-)/EW (+) / 1% (Cv + Ty) had stronger antimicrobial and antioxidant effects than all of the other treatments on carp fillets during drying, and could be a good alternative to artificial preservatives in food industry. (c) 2005 Elsevier B.V. All rights reserved.

A new technology for fish preservation by combined treatment with electrolyzed NaCl solutions and essential oil compounds
BSM Mahmoud, K Yamazaki, K Miyashita, Shin, II, T Suzuki
FOOD CHEMISTRY, 99, 4, 656, 662, ELSEVIER SCI LTD, 2006, [Peer-reviewed]
English, Scientific journal, This study was undertaken to establish a new technology, using pre-treatment with electrolyzed NaCl solutions and essential oil compounds, to extend the shelf-life of carp fillets. Samples of skinless carp fillets were treated with 100-fold (by weight) of electrolyzed NaCl solutions [cathodic solution, EW(-) and/or anodic solution, EW(+)] and 1% oil (0.5% carvacrol + 0.5% thymol) [1%(C + T)]. Then chemical [pH, volatile basic nitrogen, peroxide value, and thiobarbituric acid], microbiological (total viable count) and sensory analyses were used to evaluate the preservative effect of this new technology during storage at 5 and 25 degrees C. Our results from the chemical assays indicated that EW(-), followed by EW(+) and subsequently 1%(C + T) [EW(-)/EW(+)/1%(C + T)], significantly suppressed the lipid oxidation compared with other treatments. Data from sensory evaluation and microbiological assay showed that treatment with EW(-)/ EW(+)/1%(C + T) extended the shelf-life of carp fillets to 16 and 1.3 days compared with 4 and 0.3 days for the control samples during storage at 5 and 25 degrees C, respectively. (c) 2005 Elsevier Ltd. All rights reserved.

Cytochrome c and bioenergetic hypothetical model for alkaliphilic Bacillus spp.
T Goto, T Matsuno, M Hishinuma-Narisawa, K Yamazaki, H Matsuyama, N Inoue, Yumoto, I
JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 100, 4, 365, 379, SOC BIOSCIENCE BIOENGINEERING JAPAN, Oct. 2005, [Peer-reviewed]
English, Although a bioenergetic parameter is unfavorable for production of ATP (Delta pH < 0), the growth rate and yield of alkaliphilic Bacillus strains are higher than those of neutralophilic Bacillus subtilis. This finding suggests that alkaliphiles possess a unique energy-producing machinery taking advantage of the alkaline environment. Expected bioenergetic parameters for the production of ATP (Delta pH and Delta psi) do not reflect the actual parameters for energy production. Certain strains of alkaliphilic Bacillus spp. possess large amounts of cytochrome c when grown at a high pH. The growth rate and yield are higher at pH 10 than at pH 7 in facultative alkaliphiles. These findings suggest that a large amount of cytochrome c at high pHs (e.g., pH 10) may be advantageous for sustaining growth. To date, isolated cytochromes c of alkaliphiles have a very low midpoint redox potential (less than +100 mV) compared with those of neutralophiles (approximately +220 mV). On the other hand, the redox potential of the electron acceptor from cytochrome c, that is, cytochrome c oxidase, seems to be normal (redox potential of cytochrome a=+250 mV). This large difference in midpoint redox potential between cytochrome c and cytochrome a concomitant with the configuration (e.g., a larger negative ion capacity at the inner surface membrane than at the outer surface for the attraction of H+ to the intracellular membrane and a large amount of cyrochrome c) supporting H+-coupled electron transfer of cytochrome c may have an important meaning in the adaptation of alkaliphiles at high pHs. This respiratory system includes a more rapid and efficient H+ and e(-) flow across the membrane in alkaliphiles than in neutralophiles.

Purification and characterization of warnericin RB4, anti-Alicyclobacillus bacteriocin, produced by Staphylococcus warneri RB4
M Minamikawa, Y Kawai, N Inoue, K Yamazaki
CURRENT MICROBIOLOGY, 51, 1, 22, 26, SPRINGER, Jul. 2005, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, In this study we characterized a bacteriocin, warnericin RB4, produced by Staphylococcus warneri RB4. Warnericin RB4 activity was completely inactivated by trypsin and actinase E. The activity was stable at 100 degrees C for 15 min, and had a pH range of 2 to 6. S. warneri R134 showed antibacterial activity against only Alicyclobacillus acidoterrestris, A. acidocaldarius, and Micrococcus luteus, among 34 bacterial species tested. The amino acid sequence of the purified bacteriocin contained 27 amino acid residues (K-K-K-S-G-V-I-P-X-V-X-H-D-X-H-M-N-X-F-Q-F-V-F-X-X-X-S). The molecular mass of the bacteriocin was estimated to be 2,958.2 Da by ESI-MS. These results show that the Warnericin RB4 exhibiting specific antibacterial activity against thermo-acidophiles, Alicyclobacillus spp., is a Nukacin ISK-1 or closely related bacteriocin, classified with class IA (Lacticin 481 types). This is the first report that Warnericin RB-4 is effective to inhibit the growth of causative microorganisms of spoilage in various acidic drinks. Warnericin RB4 might prove useful in fruit juices and fruit juice-containing drinks.

Mode of action of piscicocin CS526 produced by Carnobacterium piscicola CS526
M Suzuki, T Yamamoto, Y Kawai, N Inoue, K Yamazaki
JOURNAL OF APPLIED MICROBIOLOGY, 98, 5, 1146, 1151, BLACKWELL PUBLISHING LTD, 2005, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Aims: Piscicocin CS526 is a unique class IIa bacteriocin produced by Carnobacterium piscicola CS526. The mode of action against the sensitive strain Listeria monocytogenes IID581 was evaluated.
Methods and Results: Piscicocin CS526 was adsorbed on both sensitive and insensitive gram-positive and gram-negative bacterial cells. Treatment of L. monocytogenes cells with trypsin, lipase and Triton X-100 did not reduce subsequent adsorption of piscicocin CS526. The activity of piscicocin CS526 against L. monocytogenes cells was bactericidal rather than bacteriostatic, but did not cause bacteriolysis. Piscicocin CS526 induced the efflux of K+ ions from the target cells which cause dissipation of the transmemberane potential (Delta Psi) of the cell membrane. Moreover, after exposure to piscicocin CS526, intracellular adenosine 5'-triphosphate (ATP) level of the target cells rapidly reduced without leakage of ATP from the cells, indicating that ATP depletion occurred in the cells.
Conclusion: Pore formation by piscicocin CS526 caused a rapid efflux of small molecules such as K+ from the indicator cells and dissipation of proton motive force (PMF), which lead to the cell death.
Significance and Impact of the Study: Molecular mechanism of action of piscicocin CS526 is very similar to that of other pediocin-like bacteriocins, although piscicocin CS526 possesses a unique N-terminal sequence in which Val is substituted for by Leu in the amino acid at position 7.

Purification and characterization of a novel class IIa bacteriocin, piscicocin CS526, from surimi-associated Carnobacterium piscicola CS526
K Yamazaki, M Suzuki, Y Kawai, N Inoue, TJ Montville
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 71, 1, 554, 557, AMER SOC MICROBIOLOGY, Jan. 2005, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, The bacteriocin piscicocin CS526 was inactivated by proteolytic enzymes, was stable at 100degreesC for 30 min, had a pH range of 2 to 8, and was active against Enterococcus, Listeria, Pediococcus, and Leuconostoc. The N-terminal sequence was YGNG (L) under bar, not the YGNG (V) under bar consensus motif common in class IIa bacteriocins (alternate residues underlined). The molecular mass of piscicocin CS526, which had a bactericidal mode of action, was similar to4,430 Da.

Antimicrobial substances from rhizomes of the giant knotweed Polygonum sachalinense against the fish pathogen Photobacterium damselae subsp piscicida
H Kumagai, Y Kawai, R Sawano, H Kurihara, K Yamazaki, N Inoue
ZEITSCHRIFT FUR NATURFORSCHUNG C-A JOURNAL OF BIOSCIENCES, 60, 1-2, 39, 44, VERLAG Z NATURFORSCH, Jan. 2005, [Peer-reviewed]
English, Scientific journal, The antimicrobial compounds against the fish pathogen Photobacterium damselae subsp. piscicida were isolated from Polygonum sachalinense rhizomes. The structures of the antimicrobial compounds I and 2 were determined by H-1 and C-13 NMR, 2D-NMR (COSY, HSQC, HMBC and ROESY) and FAB-MS to be phenylpropanoid glycosides, vanicoside A and B, respectively. Both compounds have feruloyl and p-coumaroyl groups bonded to a sucrose moiety in their structures. Vanicoside A also has an acetyl group in the sucrose moiety. The MIC values for vanicoside A and B against Ph. damselae subsp. piscicida DPp-1 were 32 and 64 mu g/ml, respectively. The antimicrobial activities of these vanicosides were modest, in contrast to higher activities (MICs at < 4 mu g/ml) of antibiotics, florphenicol, ampicillin and amoxicillin, which have been generally used for treating pasteurellosis. The activities of the vanicosides, however, were higher than those (MICs at 256 mu g/ml) of ferulic acid and p-coumaric acid. It was suggested that the structure of phenylpropanoids esterified with sucrose was essential for higher antimicrobial activity of vanicosides and also acetylation of sucrose might affect the activity against the bacterium.

Fate of Listeria monocytogenes in Japanese Fishery Product
YAMAMOTO TATSUHIKO, NISHIMURA(TATEYAMA, TOMOKO, YAMAZAKI KOJI, KAWAI YUJI, INOUE NORIO
日本食品微生物学会雑誌, 21, 4, 254, 259, 31 Dec. 2004, [Peer-reviewed], [Corresponding author]
Japanese

Enhancement of antilisterial activity of essential oil constituents by nisin and diglycerol fatty acid ester
K Yamazaki, T Yamamoto, Y Kawai, N Inoue
FOOD MICROBIOLOGY, 21, 3, 283, 289, ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD, Jun. 2004, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, Plant-derived essential oil components in combination with nisin and diglycerol fatty acid esters were investigated for their antibacterial activity against Listeria monocytogenes. Carvacrol and thymol were found to have the strongest antilisterial properties, followed by eugenol, cinnamaldehyde and isoeugenol. The antilisterial activity of the other essential oils (limonene, pinene, ally lisothiocyanate and linalool) was found to be low, even at the highest concentration used (0.1%). Among the diglycerol esters of fatty acids with different carbon chain lengths, diglycerol monolaurate was the most active against L. monocytogenes. A combined antilisterial effect was observed between nisin and the essential oils (carvacrol, thymol and eugenol); moreover, the addition of diglycerol monolaurate as a third preservative factor led to further combined antilisterial activities between the essential oil constituents (carvacrol, thymol and eugenol) and nisin even at lower, sub-lethal concentrations. These results indicate that nisin and diglycerol monolaurate can be used to enhance the antilisterial activity of essential oils, allowing for a reduction in the dosage used in food preservation and thereby resulting in the reduction of undesirable flavors. (C) 2003 Elsevier Ltd. All rights reserved.

Antimicrobial activity of giant knotweed Polygonum sachalinense extractes against animal pathogenic bacteria
Kawai, Y, R. Sawano, H. Kumagai, K. Yamazaki, H. Suzuki, M. Tedzuka, N. Inoue
Bull. Fish. Sci. Hokkaido Univ, 55, 3, 139, 144, 北海道大学大学院水産科学研究科 = GRADUATE SCHOOL OF FISHERIES SCIENCES, HOKKAIDO UNIVERSITY, 2004
English, Scientific journal

The induction and control of oxidation damage caused by arsenic and UV radiation exposure to Euglena gracilis SMZ
Sato, I, J. Ng, K.Yamazaki, L. R.Juneja, T.Suzuki
Trace Nutr. Res., 21, 1, 5, 微量栄養素研究会事務局, 2004, [Peer-reviewed]
English, Scientific journal

Decontamination effect of electrolysed NaCl solutions on carp
BSM Mahmoud, K Yamazaki, K Miyashita, S Il-Shik, C Dong-Suk, T Suzuki
LETTERS IN APPLIED MICROBIOLOGY, 39, 2, 169, 173, BLACKWELL PUBLISHING LTD, 2004, [Peer-reviewed]
English, Scientific journal, Aims: To evaluate the efficacy of electrolysed NaCl solutions (EW) for disinfecting bacterial isolates from carp, and the potential application of EW to reducing the bacterial load in whole carp and carp fillets.
Methods and Results: EW was produced by using a two-compartment batch-type electrolysed apparatus. Pure cultures (in vitro), whole carp (skin surface) and carp fillets were treated with EW to detect its antimicrobial effects. The anodic solution [EW (+)] completely inhibited growth of the isolates. Furthermore, dipping the fish samples in EW (+) reduced the mean total count of aerobic bacteria on the skin of whole carp and in fillets by 2.8 and 2.0 log(10)(10)(10)(, respectively. The cathodic solution [EW (-)] also reduced growth of the isolates from carp by ca 1.0 log)(. Moreover, the total counts of aerobic bacteria in whole carp (on the skin) and fillets were reduced by 1.28 and 0.82 log), respectively.
Conclusions: EW (+) has a strong bactericidal effect on bacteria isolated from carp.
Significance and Impact of the Study: Treatment with EW (+) could extend the shelf life of these fish.

Bacterial microflora of carp (Cyorinus carpio) and its shelf-life extension by essential oil compounds　　　　　　　　　　　　　　　
Mahmound, B.S.M, K. Yamazaki, K, Miyashita, I.-S. Shin, D.-S. Chang, T. Suzuki
Food Microbiology, 21, 657, 666, 2004, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal

人工海水中におけるListeria monocytogenesの生残性
山崎浩司, 高橋実, 川合祐史, 猪上徳雄
日本食品微生物学会雑誌, 20, 4, 185, 190, Japanese Society of Food Microbiology, Dec. 2003, [Peer-reviewed], [Lead author, Corresponding author]
Japanese, Scientific journal, The survival of Listeria monocytogenes IID 581 was determined in filtered sterilized artificial seawater (ASW), natural seawater (NSW) and ultra pure water (UPW) microsoms. L. monocytogenes IID581 maintained the culturable state longer at lower temperature in ASW and NSW. However, the pathogen lost culturability in UPW rapidly at all temperatures examined (5, 10 and 30°C).
The culturability of L. monocytogenes IID 581 cells was determined by spread plate count (TSAYE), and the cell activity was observed under a fluorescence microscope, using the LIVE/DEAD BacLight^TM bacteria viability kit. There were significant differences between the results obtained from those two methods at all temperatures (10, 20 and 30°C) in ASW. Greater differences were seen between the above two methods in ASW at higher temperature, while there was little difference between them in UPW. The results indicate that L. monocytogenes IID581 enters a viable but non-culturable (VBNC) state in ASW and both temperature and the concentration of inorganic salts influence the transition to the VBNC state.

Inhibition of Listeria monocytogenes in cold-smoked salmon by Camobacterium piscicola CS526 isolated from frozen surimi
K Yamazaki, M Suzuki, Y Kawai, N Inoue, TJ Montville
JOURNAL OF FOOD PROTECTION, 66, 8, 1420, 1425, INT ASSOC FOOD PROTECTION, Aug. 2003, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, Strain CS526 was isolated from frozen surimi and identified as a bacteriocin producer that had strong inhibitory activity against Listeria monocytogenes. Strain CS526 was identified as Carnobacterium piscicola by partial 16S rDNA sequence similarity. The ability of this bacteriocinogenic strain and nonbacteriocinogenic C. piscicola JCM5348 to inhibit the growth of L. monocytogenes was examined in culture broth incubated at 12degreesC and cold-smoked salmon stored at 4, 12, and 20degreesC. L. monocytogenes viable counts in the culture broth rapidly declined from 106 colony-forming units per ml to less than 10 colony-forming units per ml within 1 day at 12degreesC in the presence of C. piscicola CS526. At 4 and 12degreesC, inhibition of L. monocytogenes on salmon depended on the initial inoculurn level of C. piscicola CS526. However, C piscicola CS526 was bactericidal to L. monocytogenes within 21 and 12 days at 4 and 12degreesC in cold-smoked salmon, respectively, even when the initial inoculum levels were low. C. piscicola CS526 suppressed the maximum cell number of L. monocytogenes by two and three log cycles, even at 20degreesC. However, C. piscicola JCM5348 did not prevent the growth of the pathogen, except at 4degreesC. Bacteriocin was detected in the samples coinoculated with C. piscicola CS526. The study shows that C. piscicola CS526 might have potential for biopreservation of refrigerated foods against L. monocytogenes.

Pseudomonas alcaliphila sp nov., a novel facultatively psychrophilic alkaliphile isolated from seawater
Yumoto, I, K Yamazaki, M Hishinuma, Y Nodasaka, A Suemori, K Nakajima, N Inoue, K Kawasaki
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, 51, 349, 355, SOC GENERAL MICROBIOLOGY, Mar. 2001, [Peer-reviewed]
English, Scientific journal, Facultatively psychrophilic alkaliphilic strains were isolated from seawater obtained off the coast of Rumoi, Hokkaido. Japan. They were Gram-negative, aerobic straight rods with polar flagella, The isolates were catalase- and oxidase-positive and able to grow at 4 degreesC, but not at 40 degreesC, They produced acid from D-glucose under aerobic conditions. The isolates reduced nitrate to nitrite and hydrolysed casein and gelatin, but not starch or DNA, NaCl was required for growth at ph 10 but was not required at neutral ph, The major isoprenoid quinone was ubiquinone-9 (0-9) and the DNA G+C content was 62.3-63.2 mol%, The whole-cell fatty acids mainly consisted of C-16:0, C-16:1(9c) and C-18:1(9c), with 3-OH C-10:0 and 3-OH C-12:0 as the hydroxyl fatty acids. A larger amount of trans-unsaturated fatty acid, C-16:1(9t) was observed when the cells were grown at ph 7 compared to when cells were grown at pH 10. Phylogenetic analysis based on Dentistry,165 rRNA gene sequencing indicated that the bacteria are members of the genus Pseudomonas. Analysis of DNA-DNA relatedness data with several close National Institute of phylogenetic neighbours revealed a low level of hybridization (less than 61%), On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, it is concluded that these isolates represent a separate new Japan species. Accordingly, the name Pseudomonas alcaliphila is proposed. The type strain is AL15-21(T)(= JCM 10630(T) = IAM 14884(T)).

Occurrence of Listeria monocytogenes in retail fish and processed seafood products in Japan
K Yamazaki, T Tateyama, Y Kawai, N Inoue
FISHERIES SCIENCE, 66, 6, 1191, 1193, JAPANESE SOC FISHERIES SCIENCE, Dec. 2000, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal

Identification of facultatively alkaliphilic Bacillus sp strain YN-2000 and its fatty acid composition and cell-surface aspects depending on culture pH
Yumoto, I, K Yamazaki, M Hishinuma, Y Nodasaka, N Inoue, K Kawasaki
EXTREMOPHILES, 4, 5, 285, 290, SPRINGER-VERLAG, Oct. 2000, [Peer-reviewed]
English, Scientific journal, Facultatively alkaliphilic Bacillus sp. strain YN-2000 was isolated from an indigo ball. Although the strain has been extensively investigated as a representative strain of alkaliphilic bacillus, its taxonomic position is not yet known. Morphological, biochemical, and physiological characteristics and chemotaxonomic properties indicated that the strain was closely related to Bacillus cohnii; this was confirmed by the high homology of the 16S rRNA sequence and the construction of a phylogenetic tree on the basis of the 16S rRNA sequence and DNA-DNA relatedness data. Strain YN-2000 contained a larger amount of unsaturated fatty acids compared with Bacillus subtilis and the obligate alkaliphile, Bacillus alcalophilus, regardless of its culture pH. When the cells were grown at pH 10, the unsaturated fatty acid content and anteiso-/iso-branched fatty acid ratio became lower than those at pH 7. This result suggests that membrane fluidity decreases when the cells are grown at pH 10 compared to those of pH 7. In the cells of strain YN-2000 grown at pH 10, the cell-surface aspect was rougher, the cell shape was longer, and the cell-surface layer was thicker compared with those of the cells grown at pH 7. The cell-surface structural change might be related to adaptation to an alkaline environment.

Use of nisin for inhibition of Alicyclobacillus acidoterrestris in acidic drinks
K Yamazaki, M Murakami, Y Kawai, N Inoue, T Matsuda
FOOD MICROBIOLOGY, 17, 3, 315, 320, ACADEMIC PRESS LTD, Jun. 2000, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, The inhibitory effects of nisin on the growth of the thermoacidophilic spoilage bacterium Alicyclo-bacillus acidoterrestris were investigated for the purpose of preventing fiat-sour-type spoilage in acidic drinks. Minimum inhibitory concentration values of nisin against the spores were from less than 0.78 to 12.5 IU ml(-1) and from 25 to 100 IU ml(-1) on mYPGA plates at pH 3.4 and 4.2, respectively. The levels of nisin inhibition against the vegetative cells were, however, higher than those of the spores. In determining the effects of nisin, on the thermal resistance of A. acidoterrestris spores, the addition of nisin, contributed to the reduction of the thermal resistance of A. acidoterrestris spores in acidic drinks. Furthermore, the outgrowth of A. acidoterrestris spores was inhibited by the addition of 25-50 lU ml(-1) nisin in both orange and fruit-mixed drinks, but was not inhibited by the higher level (600 IU ml(-1)) addition in a clear-apple drink. From these findings, we conclude that if would be useful to add nisin for preventing the spoilage caused by A, acidoterrestris in all but clear-apple acidic drinks. (C) 2000 Academic Press.

Thermal resistance of Alicyclobacillus acidoterrestris spores in different buffers and pH
M Murakami, H Tedzuka, K Yamazaki
FOOD MICROBIOLOGY, 15, 6, 577, 582, ACADEMIC PRESS LTD, Dec. 1998, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, The influence of buffers and pH on the thermal resistance of a novel flat sour-type of spoilage bacterium, Alicyclobacillus acidoterrestris, was investigated At a low concentration (20 mM) decimal reduction times (D-values) in citrate and phosphate buffers were 13.6 and 12.9 min, respectively, showing little variation. At a high concentration (100 mM), however, the D-value in citrate buffer, 14.4 min, was significantly higher than that in the phosphate buffer, 12.3 min. D-values in McIlvaine buffers did not vary widely within the pH range of 3.0 to 8.0. At 88, 90, 92 and 95 degrees C in McIlvaine buffers, D-values were 24.1 -29.1, 14.8-16.8, 5.7-7.1 and 2.2-2.8 min, respectively. The thermal resistance of A. acidoterrestris spores was affected very little by varying the pH of the heating menstruum. The Z-values also did not vary widely as the pH varied among the different buffers, ranging from 6.4 to 7.1 degrees C. it was evident that A. acidoterrestris spores showed a special relationship, unknown among other Bacterial spores, between their thermal resistance and the pH of the heating menstruum. Therefore, A. acidoterrestris should be targeted when the quality of acidic food products is being tested (C) 1998 Academic Press.

Bacillus horti sp. nov., a new Gram-negative alkaliphilic Bacillus
Yumoto, I, K Yamazaki, T Sawabe, K Nakano, K Kawasaki, Y Ezura, H Shinano
INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY, 48, 565, 571, SOC GENERAL MICROBIOLOGY, Apr. 1998, [Peer-reviewed]
English, Scientific journal, Novel Cram-negative alkaliphilic strains were isolated from soil obtained from Atsuma, Hokkaido, Japan. The isolates were strictly aerobic rods that produced subterminally located ellipsoidal spores. Chemotaxonomic characteristics of the isolates included the presence of meso-diaminopimelic acid in the cell wall and a DNA G+C content of 40.2-40.9 mol%. The major isoprenoid quinone was menaquinone-7 and the cellular fatty acid profile consisted of a significant amount of 15.C branched-chain acids, iso-C-15:0 and anteiso-C-15:0. The growth rate was higher at ph 8-10 than at ph 7. Comparative sequence analysis of 16S rDNA of 14 alkaliphilic Bacillus strains indicates that the isolated strain has an equidistant relationship to three already defined rRNA groups of alkaliphilic Bacillus species. Based on the morphological and physiological characteristics, as well as phylogenetic position as determined by 16S rDNA analysis and DNA-DNA relatedness data, it is concluded that these isolates should be designated as a new species, for which the name Bacillus horti is proposed. The type strain is K13(T)(= JCM 9943(T)).

Isolation of Vibrio sp. S-1 exhibiting extraordinarily high catalase activity
Yumoto, I, K Yamazaki, K Kawasaki, N Ichise, N Morita, T Hoshino, H Okuyama
JOURNAL OF FERMENTATION AND BIOENGINEERING, 85, 1, 113, 116, SOC FERMENTATION BIOENGINEERING, JAPAN, 1998, [Peer-reviewed]
English, Scientific journal, A bacterium exhibiting extraordinarily high catalase activity was isolated from a drain pool of a fish product processing plant that uses H2O2 as a bleaching and microbicidal agent. The isolate was a gram-negative, rod-shaped, oxidase-positive, facultative anaerobe capable of both fermentative and respiratory metabolism, and sensitive to vibriostatic compound O/129. Although the isolate was non-flagellated, its taxonomic characteristics and phylogenetic position based on a 16S rRNA analysis indicated that it belonged to the genus Vibrio. A culture medium containing living cells and a cell-free extract prepared from 48-h cultured cells of the isolate exhibited catalase activity of 680 units/mg cells and 7276 units/mg protein, respectively. The activity of the cell-free extract of the isolate was 2 orders greater than those of Escherichia coli and Bacillus subtilis. Application of the newly isolated bacterium or its enzyme will provide an effective means of decomposing H2O2 contained in industrial waste such as that produced in the paper, food, textile, and semiconductor industries.

Changes in solubility and ATPase activity of carp myofibrils during frozen storage under phosphate buffer conditions
H Kitazawa, Y Kawai, K Yamazaki, N Inoue, H Shinano
FISHERIES SCIENCE, 63, 4, 630, 634, JAPAN SOC SCI FISHERIES TOKYO UNIV FISHERIES, Aug. 1997, [Peer-reviewed]
English, Scientific journal, The solubility and specific ATPase activity of carp myofibrils suspended in 5 and 50 mM phosphate buffer (pH 6.8) were compared at three different storage temperatures, -4, -11, and -26 degrees C, in the absence of neutral salts throughout a period of 167 days. Allocated ATPase activities in salt-soluble and salt-insoluble fractions were also calculated from solubility and specific ATPase activity. The extent of the decrease in solubility and in the four kinds of allocated ATPase activity in the salt-soluble fraction was smaller with a decrease in storage temperature at both buffer concentrations. It is suggested that myofibril insolubilization occurred without complete inactivation of ATPase activity.

Influence of sporulation medium and divalent ions on the heat resistance of Alicyclobacillus acidoterrestris spores
K Yamazaki, Y Kawai, N Inoue, H Shinano
LETTERS IN APPLIED MICROBIOLOGY, 25, 2, 153, 156, BLACKWELL SCIENCE LTD, Aug. 1997, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, The influence of divalent cations on the heat resistance of spores of the thermoacidophilic spoilage bacterium Alicyclobacillus acidoterrestris was studied. The heat resistance of A. acidoterrestris spores was not affected by the presence of the different divalent cations (Ca2+, Mg2+, Ba2+, Mn2+ and Sr2+) in the sporulation medium, and by the demineralization or remineralization. And the Ca and Mn contents in A. acidoterrestris spores were scarcely changed by these treatments. However, the heat resistance of Bacillus subtilis spores was affected with the changes of Ca content in the spores. The Ca contents in A. acidoterrestris spores of the different forms were greater than the DPA content. In contrast, the DPA content in the B. subtilis spores was greater than the Ca content. These findings suggest that the presence of constant amount of Ca-DPA and a stronger binding characteristic of divalent ions, especially Ca and Mn, is reflected in the specific heat resistance of A. acidoterrestris spores.

Randomly amplified polymorphic DNA (RAPD) for rapid identification of the spoilage bacterium Alicyclobacillus acidoterrestris
K Yamazaki, T Okubo, N Inoue, H Shinano
BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 61, 6, 1016, 1018, TAYLOR & FRANCIS LTD, Jun. 1997, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, RAPD (randomly amplified polymorphic DNA) analysis was developed for rapid identification of the spoilage bacterium, Alicyclobacillus acidoterrestris. Three primers, Ba-10, F-61, and F-64, allowed adequate discrimination between strains of A. acidoterrestris and related bacteria in RAPD analyses, As compared with the conventional method and a RAPD assay against the isolates from various environmental and food samples, the results obtained from the RAPD pattern were identical to the identification by the conventional method, We suggest that the RAPD analysis is a rapid and reliable technique to distinguish A. acidoterrestris from other related bacteria.

Antimicrobial activities of extracts from sachalune giant knotweed Polygonum sachalinense
Saito, M, Y.Kawai, K.Yamazaki, N.Inoue, H.Shinano
Food Sci. Technol. Int. Tokyo, 3, 3, 290, 293, Japanese Society for Food Science and Technology, 1997, [Peer-reviewed]
English, Scientific journal, The antimicrobial activities of extracts from the leaves and rhizomes of Sachaline giant knotweed, Polygonum sachalinense, were examined. Of all the fractions separated using various solvents from the methanol extracts, the ethyl acetate fractions obtained from both the leaves and rhizomes had the highest antibacterial activity. Chloroform-separated fractions obtained from the rhizomes also displayed high antibacterial activity against some bacterial strains. Ethyl acetate-soluble fractions obtained from both the leaves and rhizomes showed effective growth inhibition against Bacillus brevis, Bacillus cereus, Bacillus coagulans, Curtobacterium flaccumfaciens, Staphylococcus aureus, Aeromonas hydrophila and Pseudomonas fluorescens.

Aggregation in subunit components of carp myofibrils during frozen storage under phosphate buffer conditions
Kitazawa,H, Y.Kawai, K.Yamazaki, N.Inoue
Fisheries Sci., 63, 635, 638, 1997, [Peer-reviewed]
English, Scientific journal

Chemical and microbiological characteristics of sardine meal fermented with Aspergillus oryzae IFO 4202
Kakio,M, Y.Kawai, M.Kunimoto, K.Yamazaki, N.Inoue, H. Shinano
Food Sci. Technol. Int. Tokyo,, 3, 1, 61, 68, Japanese Society for Food Science and Technology, 1997, [Peer-reviewed]
English, Scientific journal, Sardine moist meals were inoculated with Aspergillus oryzae IFO 4202 seed and fermented. Accompanying the growth of the fungus, the chemical composition of the meals significantly changed during incubation. The fermentation contributed to antioxidation of lipids and reduction of histamine. Glucose supplement during fermentation was effective in inhibiting the production of volatile basic nitrogenous compounds. Fermented meals maintained superior quality of the proteins, protecting amino acid residues during incubation. The initial bacterial cell counts in meals were 3×10² CFU/g and reached 10⁸ CFU/g in 72-h incubation. The Gram-negative rod-shaped bacteria, Pseudomonas spp., Moraxella spp. and Acinetobacter spp., were predominant in the initial meals. Gram-positive bacteria, especially Micrococcus spp., gradually became predominant during incubation. Fermentation and glucose supplement enhanced this predominancy of Micrococcus spp. during incubation. Fermentation with Aspergillus oryzae in the presence of glucose was considered to be effective for improvement of the chemical, nutritional and microbiological quality of fish meals.

Comparative sequence analyses of the genes coding for 16S rRNA of Lactobacillus casei-related taxa
K Mori, K Yamazaki, T Ishiyama, M Katsumata, K Kobayashi, Y Kawai, N Inoue, H Shinano
INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY, 47, 1, 54, 57, AMER SOC MICROBIOLOGY, Jan. 1997, [Peer-reviewed]
English, Scientific journal, The primary structures of the 16S rRNA genes of the type strains of Lactobacillus casei and related taxa were determined by PCR DNA-sequencing methods. The sequences of Lactobacillus casei, Lactobacillus zeae, Lactobacillus paracasei, and Lactobacillus rhamnosus were different. The K-nuc values ranged from 0.0040 to 0.0126. On the basis of the K-nuc values and the levels of DNA-DNA relatedness among the strains of these species, the L. casei-related taxa should be classified in the following three species: L. zeae, which includes the type strains of L. zeae and L. casei; a species that includes the strains of L. paracasei and L. casei ATCC 334; and L. rhamnosus.

酸性飲料変敗菌Alicyclobacillus acidoterrestrisの耐熱性とその制御
山崎浩司, 礒田千恵子, 手塚裕和, 川合祐史, 信濃晴雄
日本食品科学工学会誌, 44, 12, 905, 911, 1997, [Lead author, Corresponding author]

Specific primers for detection of Alicyclobacillus acidoterrestris by RT-PCR
K Yamazaki, H Teduka, N Inoue, H Shinano
LETTERS IN APPLIED MICROBIOLOGY, 23, 5, 350, 354, BLACKWELL SCIENCE LTD, Nov. 1996, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, The reverse transcription-polymerase chain reaction (RT-PCR), after a short enrichment culture, was used to detect Alicyclobacillus acidoterrestris in acidic beverages. Two specific primers were selected from the region of V2 and V4 on 16S rRNA gene. With this primer set, 294-bp fragments from ii. acidoterrestris could be amplified. The detection limit of the RT-PCR with the FHLP filters was about 10(-1) fg of pure total RNA per reaction. Juice samples inoculated with 10(4) cfu of A. acidoterrestris per mi were RT-PCR positive without enrichment. However, after 15 h of enrichment, the samples inoculated with 2-3 cfu ml(-1) were positive. This RT-PCR culture assay would enable rapid and specific detection of strains of A. acidoterrestris in acidic beverages.

The dielectric properties of unfrozen water in carp myofibrils under frozen conditions
N Inoue, A Kishimoto, K Yamazaki, H Shinano
FISHERIES SCIENCE, 62, 4, 603, 605, JAPAN SOC SCI FISHERIES TOKYO UNIV FISHERIES, Aug. 1996, [Peer-reviewed]
English, Scientific journal, The dielectric properties of carp myofibrils in the presence and absence of electrolytes under frozen conditions were measured. Unfrozen water was characterized by the apparent dielectric relaxation time (tau) and apparent activation energy calculated. The unfrozen water was divided into three groups that had different relaxation mechanisms by a Cole-Cole plot. The temperature-dependence (reciprocal of absolute temperature) of tau (Arrhenius plot) presented a biphasic pattern with a breaking point at -15.3 and -23.2 degrees C in the absence and presence of electrolytes, respectively. In the temperature range from the breaking point to the lowest temperature examined, it seems that the unfrozen water is ''unfreezable water'' and corresponds to monolayer water. At the same time, it is considered that unfrozen water in the temperature range from the breaking point to the highest temperature examined corresponds to the bound water of multilayer water. The mobility of unfrozen and unfreezable waters increased in the presence of electrolytes under the temperatures examined.

Isolation and identification of Alicyclobacillus acidoterrestris from acidic beverages
K Yamazaki, H Teduka, H Shinano
BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 60, 3, 543, 545, TAYLOR & FRANCIS LTD, Mar. 1996, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, Thermophilic bacteria isolated from spoiled acidic beverages were identified on the basis of DNA-DNA homology and 16S ribosomal DNA sequence similarity to Alicyclobacillus acidoterrestris. This result suggested that the isolates were a new type of spoilage bacterium in acidic beverages in Japan.

ISOLATION AND CHARACTERISTICS OF LACTIC-ACID BACTERIA IN COMMERTIAL IKA-SHIOKARA
K MORISHITA, W OTAKASAKA, K YAMAZAKI, Y KAWAI, N INOUE, H SHINANO
FISHERIES SCIENCE, 61, 2, 371, 372, JAPAN SOC SCI FISHERIES TOKYO UNIV FISHERIES, Apr. 1995, [Peer-reviewed], [Corresponding author]
English, Scientific journal

Chemical and Microbiological Characteristics of Commercial "Shiokara".
MORISHITA KOREMOTO, OTAKASAKA WAKANA, YAMAZAKI KOJI, KAWAI YUJI, INOUE NORIO, SHINANO HARUO
北海道大学水産学部研究い報, 45, 3, 100, 107, Aug. 1994, [Corresponding author]
Japanese, Scientific journal

EFFECT OF SQUID LIVER, SKIN, AND INK ON MICROBIOLOGICAL CHARACTERISTICS OF IKA-SHIOKARA DURING RIPENING PROCESS
M TAKAI, K YAMAZAKI, Y KAWAI, N INOUE, H SHINANO
NIPPON SUISAN GAKKAISHI, 59, 9, 1617, 1623, JAPAN SOC SCI FISHERIES TOKYO UNIV FISHERIES, Sep. 1993, [Peer-reviewed], [Corresponding author]
English, Scientific journal, ''Akazukuri'', ''kurozukuri'', ''shirozukuri'' and ''kurozukuri (hakuhi)'' were prepared and comparisons made among them to detect differences in viable cell counts and microflora during the ripening process. The viable cell counts and the rate of bacterial growth were depressed by the addition of squid liver and/or ink and by the removal of skin. The squid ink had a particularly strong effect, and elongated the period of edibility. Staphylococcus epidermidis has never been isolated from ''ika-shiokara'' with the addition of ink, and was therefore isolated without ink. In the in vitro experiments, both S. epidermidis and S. aureus were inhibited by the extracts of heated squid ink. This finding suggests that there are heat stable inhibitory substances in the squid ink.

Effect of Carbon Dioxide on the Growth of Bacteria.
YAMAZAKI KOJI, KAWAI YUJI, INOUE NORIO, SHINANO HARUO
北海道大学水産学部研究い報, 43, 3, 115, 123, Aug. 1992, [Lead author, Corresponding author]
Japanese, Scientific journal

いか塩辛熟成過程中の化学的特性に及ぼす肝臓, 表皮および墨の影響
高井典子, 山崎浩司, 川合祐史, 猪上徳雄, 信濃晴雄
日水誌, 59, 1609, 1615, 1992, [Peer-reviewed], [Corresponding author]
Japanese, Scientific journal

イカ塩辛の菌相特性に及ぼすイカ肝臓の影響
山崎浩司, 北村史恵, 猪上徳雄, 信濃晴雄
日本水産学会誌, 58, 10, 1971, 1976, 1992, [Peer-reviewed], [Lead author, Corresponding author]
Japanese, Scientific journal

水産物における損傷菌-食品加工における損傷菌発生とその問題点　　　　　　　　　　　　　　　
山木将悟, 山﨑浩司, 日本防菌防黴学会誌, 47, 11, 467, 472, Nov. 2019, [Invited], [Last author, Corresponding author], [Domestic magazines]
Japanese, Introduction scientific journal

Occurrence and Prevention of Injured Bacterial Cells in Fisheries
Koji Yamazaki, Kantaro Takeuchi, Yohei Yamazaki, Sayaka Mino, Hisae Kasai, Toko Sawabe, Tomoo Sawabe, Masataka Satomi, JOURNAL OF THE JAPANESE SOCIETY FOR FOOD SCIENCE AND TECHNOLOGY-NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI, 65, 4, 197, 204, Apr. 2018, [Invited], [Lead author], [Domestic magazines]
The control of food poisoning associated with fish and fish products is challenging, even in the developed world. Injured cells of bacterial pathogens, generated by various stressors during food processing, are considered to be an important risk factor in food poisoning incidents. It is important to accumulate more knowledge on the physiology, genetics, and molecular biology of injured bacterial cells related to fish and fish products, and also to apply this knowledge to the development of new technologies. Here, we introduce recent advances in the physiology and genetics of Vibrio parahaemolyticus and Listeria monocytogenes and discuss future directions of the risk control of pathogens in fisheries., JAPAN SOC FOOD SCIENCE TECHNOLOGY, Japanese, Introduction scientific journal

食品微生物制御におけるバクテリオファージの利用　　　　　　　　　　　　　　　
山木将悟, 山崎浩司, ニューフードインダストリー, 59, 7, 15, 23, Jul. 2017, [Invited], [Last author, Corresponding author], [Domestic magazines]
Japanese, Introduction commerce magazine

Utilization of Bacteriocins to the Control of Microbial Growth in Food
山木将悟, 山崎浩司, 日本醸造協会誌, 109, 9, 636, 642, Sep. 2014, [Invited], [Last author, Corresponding author], [Domestic magazines]
近年，消費者は加熱・加工を極力控えた食品を好むようになっている。このような消費者のニーズに応えつつ食品の安全を担保することは至難の業である。そこで，著者らに食品保存料として世界で広く利用され，食品における食中毒リスクの低減と品質の向上に大きく寄与し，食品の味，香りに影響なく，ヒトの消化酵素により分解される安全な天然由来抗菌ペプチドのバクテリオシンの代表のNisin A，さらにはバクテリオシンと他の抗菌物質との組み合わせなどを解説いただいた。味噌には精製ナイシンとして，5mg/kgの使用が認可されているので，味噌業界の方はご一読いただきたい。, 日本醸造協会, Japanese, Introduction scientific journal

食品の安全を確保するための評価・管理技術の開発 第1章 有害微生物検出技術の開発 3 高感度蛍光マイクロコロニー法による食中毒細菌の複数同時検出・定量システムの開発
山崎浩司, 澤辺智雄, 農林水産省農林水産技術会議事務局研究成果, 491, 32, 37, Jan. 2013
Japanese, Technical report

Control of microorganisms in seafood using electrolyzed water and biopreservatives　　　　　　　　　　　　　　　
Kawai, Y, Yamazaki, K, Shin, Il-Shik, Proceeding of the 10th Japan-Korea Joint Seminar on Fisheries Siciences, 96, 100, 2010
English, Introduction international proceedings

Distribution and mobility of water and low molecular components in squid mantle during drying process　　　　　　　　　　　　　　　
Kawai, Y, Takehara, Y, Okumura, K, Yamazaki, K, Proceeding of the 9th Japan-Korea Joint Seminar on Fisheries Sciences, 2009
English, Introduction international proceedings

Specific detection of Listeria spp. using fluorescent in situ hybridization in combination with filter cultivation (FISHFC)　　　　　　　　　　　　　　　
Yamazaki, K, Fuchizawa, I, Kawai, Y, Sawabe, T, Ootsubo, M, Proceedings of the United States – Japan Cooperative Program in Natural Resources (UJNR) Food and Agriculture Panel 37th Annual Meeting, 60, 61, 2008
English, Introduction international proceedings

Enjoying Raw Food and Keeping Food Safety Food Safety of Seafood Consumed Raw
YAMAZAKI KOJI, KAWAI YUJI, ISSHIKI KENJI, Foods & Food Ingred J Jpn, 212, 8, 649, 653, Aug. 2007, [Invited], [Lead author], [Domestic magazines]
FFIジャーナル編集委員会, Japanese, Introduction scientific journal

Listeria monocytogenesの研究動向 抗リステリア性ペプチド産生微生物―その性質と利用―
山崎浩司, 日本食品微生物学会雑誌, 23, 4, 199, 203, Dec. 2006, [Invited]
Japanese, Introduction scientific journal

Effect of treatment with electrolyzed water, carvacrol and thymol on fish meat during drying　　　　　　　　　　　　　　　
Barakat S.M. Mahmoud, K. Yamazaki, K. Miyashita, Y. Kawai, S. Il-Shik, T. Suzuki, Proceedings of the 3rd Inter-American Drying Conference, 119, 2005
English, Introduction international proceedings

耐熱性好酸性菌の効果的制御法-バクテリオシンによる制御　　　　　　　　　　　　　　　
山崎浩司, TABシンポジウム講演集, 2004, [Invited]
Japanese, Lecture materials

Purification and Characterization of Soluble Cytochrome c from an Alkaliphilic Bacterium Pseudomonas alcaliphila
Morishita Nozomu, Inoue Norio, Yamazaki Koji, Yumoto Isao, 日本生物工学会大会講演要旨集, 13, 189, 189, 2001
日本生物工学会, Japanese

Alicyclobacillusの性質と制御法　　　　　　　　　　　　　　　
日本食品保全研究会報, 7, 2, 19, 22, 2001, [Invited]
Japanese, Lecture materials

生食のはなし　　　　　　　　　　　　　　　
川本伸一(編集代表)・朝倉宏,稲津康弘,畑江敬子,山﨑浩司(編), 第3章 魚介類
朝倉書店, Apr. 2023, 9784254431308, [Joint editor]

生食のはなし　　　　　　　　　　　　　　　
山﨑浩司, コラム「魚の鮮度と腐敗」
朝倉書店, Apr. 2023, 9784254431308, [Contributor]

食品安全検定テキスト・中級 第3版　　　　　　　　　　　　　　　
山﨑浩司, 谷口力夫, 第2章 1 ・ 2 ・ 3 食中毒起因微生物
中央法規出版, Feb. 2022, 314, 17-91, Japanese, Textbook, [Joint work]

食品製造・検査における芽胞・損傷菌とその検出・制御技術　　　　　　　　　　　　　　　
山木将悟, 山﨑浩司, 第II編 損傷菌の検出と制御 第2章5-「リステリア損傷菌の発生と制御」
シーエムシー出版, May 2020, [Joint work]

Seafood Safety and Quality　　　　　　　　　　　　　　　
MD. Latiful Bari, K. Yamazaki
CRC Press, Sep. 2018, [Joint editor]

Seafood Safety and Quality - Chapter 5　　　　　　　　　　　　　　　
Yamazaki, K, Yamaki, S, Chapter 5 - Control of pathogens in seafood products
CRC Press, Sep. 2018, [Joint work]

Seafood Safety and Quality - Chapter 3　　　　　　　　　　　　　　　
Yamaki, S, Yamazaki, K, Chapter 3 - Foodborne pathogens related to seafood products
CRC Press, Sep. 2018, [Joint work]

食と微生物の事典　　　　　　　　　　　　　　　
山崎浩司, 微生物由来の保存料
朝倉書店, Aug. 2017, [Contributor]

食と微生物の事典　　　　　　　　　　　　　　　
山崎浩司, 食品の腐敗・変敗
朝倉書店, Aug. 2017, [Contributor]

抗菌ペプチドの機能解明と技術利用　　　　　　　　　　　　　　　
山崎浩司, 第６章「乳酸菌由来の抗菌ペプチド（バクテリオシン）による食中毒菌と腐敗細菌の発育制御」
シーエムシー出版, May 2017, [Joint work]

Cold-adapted microorganisms　　　　　　　　　　　　　　　
Yumoto, I, K. Yamazaki, Ecology and Taxonomy of Psychrotolerant Bacteria in Arttificial Cold Environments
Caister Academic Press, 2013, [Contributor]

Seafood Quality, Safety and Health applications　　　　　　　　　　　　　　　
Bagenda,D.K, K. Yamazaki, Food borne pathogens in sea food and their control
Wiley-Blackwell Publishing, 2011, [Contributor]

総合調理用語辞典　　　　　　　　　　　　　　　
山崎浩司
凸版印刷, 2010, [Contributor]

食品と微生物　　　　　　　　　　　　　　　
山崎浩司, 4-1. 微生物の検査法
光琳, 2008, [Contributor]

微生物の利用と制御 – 食の安全から環境保全まで　　　　　　　　　　　　　　　
山崎浩司, D.K.Bagenda, 水産食品における微生物の利用
恒星社厚生閣, 2007, [Contributor]

食品のストレス環境と微生物 - その挙動・制御と検出　　　　　　　　　　　　　　　
山崎浩司, 第３章第３節 耐熱性好酸菌
(株)サイエンスフォーラム, 2004, [Contributor]

マリンバイオ資源の化学的機能と利用　　　　　　　　　　　　　　　
北海道大学 全学教育科目
2023 - Present, Others, Japan

水産科学汎論 II　　　　　　　　　　　　　　　
北海道大学大学院水産科学院
2023 - Present, Graduate school liberal arts course, Japan

食品衛生学　　　　　　　　　　　　　　　
北海道大学水産学部
2023 - Present, Undergraduate special subjects, Japan

水産食品科学特論 II　　　　　　　　　　　　　　　
北海道大学大学院水産科学院
2015 - Present, Postgraduate courses, Japan

水産食品科学特論 I　　　　　　　　　　　　　　　
北海道大学大学院水産科学院
2015 - Present, Postgraduate courses, Japan

微生物学実験　　　　　　　　　　　　　　　
北海道大学水産学部
2009 - Present, Undergraduate special subjects, Japan

微生物利用学　　　　　　　　　　　　　　　
北海道大学水産学部
2009 - Present, Undergraduate special subjects, Japan

健康と社会：魚をたべる　　　　　　　　　　　　　　　
北海道大学 全学教育科目
2008 - Present, Others, Japan

教科教育法（水産 I)　　　　　　　　　　　　　　　
北海道大学教育学部
2022 - 2022, Others, Japan

教科教育法（水産 I）　　　　　　　　　　　　　　　
北海道大学 教育学部
2016 - 2016, Others, Japan

環境と人間：マリンバイオマスの探索と利用　　　　　　　　　　　　　　　
北海道大学 全学教育科目
2009 - 2016, Others, Japan

食品衛生学特論　　　　　　　　　　　　　　　
北海道大学大学院水産科学院
2005 - 2014, Postgraduate courses, Japan

食品製造学実験　　　　　　　　　　　　　　　
北海道大学水産学部
1993 - 2009, Undergraduate special subjects, Japan

食品機能化学実験　　　　　　　　　　　　　　　
北海道大学水産学部
2003 - 2008, Undergraduate special subjects, Japan

食品衛生学　　　　　　　　　　　　　　　
北海道大学水産学部
2003 - 2008, Undergraduate special subjects, Japan

微生物学実験　　　　　　　　　　　　　　　
北海道大学水産学部
1998 - 2002, Undergraduate special subjects, Japan

微生物化学　　　　　　　　　　　　　　　
北海道大学水産学部
1998 - 2002, Undergraduate special subjects, Japan

Control and detection of microorganisms in food
LASBOS Moodle, Koji Yamazaki, 18 Dec. 2020, [Educational materials]

ポリフェノール類の酵素阻害機能を利用したヒスタミン食中毒リスクの低減　　　　　　　　　　　　　　　
科学研究補助金 基盤研究Ｃ（一般）
Apr. 2022 - Mar. 2025
山﨑浩司
文部科学省, Principal investigator, Competitive research funding

発酵スターター株の増殖特性評価,「日本産水産発酵食品の製造に特化したヒスタミン蓄積抑制乳酸菌発酵スターターの開発」　　　　　　　　　　　　　　　
農林水産業・食品産業科学技術研究推進事業，実用技術開発ステージ，現場ニーズ対応型・重要施策対応型
Apr. 2016 - Mar. 2019
山崎浩司
農林水産省, Competitive research funding

ヒスタミンを生成するモルガネラ・サイクロトレランスの動態解明とファージによる制御　　　　　　　　　　　　　　　
科学研究補助金 基盤研究Ｃ（一般）
2017 - 2019
山崎浩司
文部科学省, Competitive research funding

損傷リステリアの発生機構の解明と制御法の開発　　　　　　　　　　　　　　　
食品の安全性と動物衛生の向上のためのプロジェクト
Apr. 2013 - Mar. 2018
山崎浩司
農林水産省, Competitive research funding

マルチ蛍光スペクトル分析FISHFCによる食品衛生細菌迅速一括検査システムの商品モデル開発　　　　　　　　　　　　　　　
農林水産業・食品産業科学技術研究推進事業, 実用技術開発ステージ
Apr. 2013 - Mar. 2016
大坪雅史,山﨑浩司
農林水産省, Competitive research funding

溶菌性ファージを利用したヒスタミン生成菌の制御　　　　　　　　　　　　　　　
科学研究補助金 基盤研究 C (一般)
2014 - 2016
山崎浩司
文部科学省, Competitive research funding

生野菜からの病原微生物の蛍光 in situ ハイブリダイゼーション(FISH)法に基づいた多重定量法の開発　　　　　　　　　　　　　　　
生産・流通・加工工程における体系的な危害要因の特性解明とリスク低減技術の開発
Apr. 2009 - Mar. 2013
山崎浩司
農林水産省, Competitive research funding

乳酸菌バクテリオシンによる制御法の開発　　　　　　　　　　　　　　　
生産・流通・加工工程における体系的な危害要因の特性解明とリスク低減技術の開発
Apr. 2009 - Mar. 2013
川合祐史, 山﨑浩司
農林水産省, Competitive research funding

Study of characteristics and control of bacteriocin-resistant Listeria monocytogenes in seafood
Grants-in-Aid for Scientific Research
2011 - 2013
YAMAZAKI KOJI
This study was investigated the characterization of bacteriocin-resistant Listeria monocytogenes and the development of inhibition method using bacteriocin (nisin A) against L.monocytogenes in seafood products. Nisin-resistant L.monocytogenes showed that the affinity between the cell surface of the resistant strains and nisin molecule was reduced, compared with those of wild strains. And protein profiles on the cytoplasmic membrane and the structure of peptidoglycan layer of the nisin-resistant strains would be also changed. The combination of nisin A and pectin digests was effective for the control of L.monocytogenes growth in raw salmon roes seasoned with soy-sauce at refrigeration temperature, suggesting that the combination of them will be a promising tool to ensure food safety to L.monocytogenes contamination in seafood.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Competitive research funding, 23580274

Study of food biopreservation using anti-listerial peptides to ensure food safety
Grants-in-Aid for Scientific Research
2008 - 2010
YAMAZAKI Koji
This study was undertaken to establish a new technology, using anti-listerial peptides, to ensure food safety. Production of an anti-listerial peptide, piscicocin CS526, produced by Carnobacterium maltaromaticum CS526 was regulated with environmental pH. A simple one-step isolation method, based on the adsorption-desorption property to bacterial cells, was developed for piscicocin CS526. A freeze-dried bioactive fermented powder with anti-listerial peptide produced by C.maltaromaticum FS-B was effective for the control of L.monocytogenes in a food model at refrigeration and frozen temperature, suggesting that the fermented powder will be a powerful tool to ensure food safety against L.monocytogenes contamination in foods such as ready-to-eat products.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Competitive research funding, 20580216

乳酸菌由来新規抗リステリア性ペプチドの作用機構解明とその応用
科学研究補助金 若手研究(B)
2005 - 2006
山崎浩司
申請者が水産食品から分離に成功した新規抗菌ペプチド産生菌Carnobacterium piscicola CS526で乳清タンパク質を発酵・粉末化し,これを用いたready-to-eat食品モデル中でのListeria monocytogenesの制御について検討し,Piscicocin CS526含有乳清発酵粉末を挽肉に添加することで,L.monocytogenesの発育を効果的に阻止できることを明らかにした。
また,LImonocytogenesのPiscicocin CS526耐性獲得頻度について調べ,10^<-4>〜10^<-5>の割合でClass IIaバクテリオシンであるPiscicocin CS526耐性菌が出現することを明らかにした。一方・食品中でのPiscicocin CS526耐性L.monocytogenesの制御を考え,様々な抗菌物質に対するPiscicocin CS526耐性菌の交差耐性の有無を調べ,各種抗生物質や食品への添加が許可されている既存の抗菌物質約30種に対して交差耐性のないことを示した。また,耐性株では親株に比べてPiscicocinCS526の細胞吸着量が低下していることを明らかにし,耐性株での細胞膜表面の負電荷領域の減少が耐性獲得の原因のひとつであることを明らかにした。さらに,他の抗菌性物質との併用によりL.monocytogenesのregrowthを阻止できることから耐性獲得が抑制されることを示した。
文部科学省, 若手研究(B), 北海道大学, Competitive research funding, 17780163

水産食品におけるリステリア菌の動態解明と制御に関する研究
科学研究費補助金 基盤研究C(2)
2001 - 2002
川合祐史,山﨑浩司
文部科学省, 奨励研究(A), 北海道大学, Competitive research funding, 13760151

Studies on rapid molecular method for detection of new histamine-producing bacteria and new acidophilic spoilage bacteria.
Grants-in-Aid for Scientific Research
1996 - 1998
FUJII Tateo, SHINANO H., YAMAZAKI K, INOUE T., YOKOMOTO Y., KIMURA B.
1. Fujii and Kimura(Tokyo University of Fisheries), Yokomoto(Perkin Elmer, Japan)
The purpose of this study was to establish a rapid molecular method for detecting histamine-producing bacteria, the causative agent of scombroid poisoning. The Photobacterium histaminum hdc gene encoding an inducible histidine decarboxylase(HisDcase), that is involved in a large scale excretion of histamine extracellularly, has been cloned by using the N-terminal amino acid sequence of the purified protein. The cloned chromosomal fragment containing the hdc gene was sequenced. Oligonucleotide primers were designed for the PCR amplification of hdc genes of P.histaminum and several other gram-negative histamine-producing bacteria. The optimal PCR conditions for detecting histamine-producing bacteria were evaluated.
Also, the TaqMan PCR assay for rapid detection of bacteria was evaluated, using Salmonella. This system uses the 5' nuclease activity of Taq DNA polymerase which digests an internal fluorogenic probe to monitor the amplification of the target gene. These results indicate that TaqMan is a reliable and rapid method for Salmonella analysis in the food industry.
2. Shinano, Inoue, Yamazaki (Hokkaido University)
Using specific region of 16S rRNA gene, RT-PCR method enabled the detection of A.acidoterrestris, a new type of thermoacidophilic spoilage bacterium in acidic beverages. A PCR method for Clostridium perfringens with fluorogenic probes was also developed. Additionally, PCR fragment length typing of the internal spacer region between the 16S and 23S rRNA genes was found to be rapid and reliable to distinguish C.perfringens among clostridia. DNA/RNA extracting methods from food, developed in this study, were proved to be practical.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Tokyo University of Fisheries, Competitive research funding, 08556034

イカ墨に含まれる抗菌性物質の探索とその応用に関する研究
科学研究費補助金 奨励研究(A)
1996 - 1996
山崎浩司
イカ墨中の抗菌性物質を検索するため,まず様々な種類のイカ墨の抗菌性について比較検討した。その結果,Staphylococcus aureusとS. epidermidisの発育に対して,スルメイカおよびモンゴイカ墨でほぼ同等の発育遅延効果を認めた。しかしヤリイカ墨には発育遅延効果は認められなかった。またこれらスルメイカおよびモンゴイカ墨の抗菌性は,イカ塩辛の熟成初期および中期に優勢となる S. warneri, S. xylosusまたはMicrococcus spp.の発育には影響を示さなかった。
次に,モンゴイカ墨の抗菌特性についてS. epidermidisとS. warneriを指標菌に用い検討した結果,イカ墨濃度3%以上および食塩濃度10%以上の条件下においてその抗菌性が発揮されることが明らかとなった。また作用pHについて検討した結果,イカ塩辛熟成初期と同等のpH6前後では,発育抑制効果が認められたが,pH6.4以上になるとその効果が静菌効果に減弱してしまうことを見出した。しかし,「イカ塩辛黒作り」の熟成期間を通じて優勢となるS. warneriに対してはpH6付近では発育遅延効果は見られず,さらにイカ墨が存在しない場合にはpH7に近づくにつれて発育速度が徐々に低下するのに対して,墨存在下ではいずれのpHにおいても発育速度には変化は見られなかった。
これらのことから,「黒作り」が「赤作り」と比較して,S. warneriが優勢となるより単純な菌相を形成することおよび食中毒菌であるS. aureusが検出されない理由のひとつに,熟成巾におけるpH変動と連動したイカ墨成分のS. warneriに対する増殖促進作用とS. epidermidisに対する増殖抑制作用およびイカ墨成分のS. aureusに対する抗菌作用が上手く発揮されるためと推察した。
文部科学省, 奨励研究(A), 北海道大学, Competitive research funding, 08760193

16SrRNA塩基配列に基づく低酸性飲料缶詰変敗原因菌の迅速検出に関する研究
研究費補助金 奨励研究(A)
1994 - 1994
山崎浩司
低酸性飲料変敗原因菌の迅速検出法を確立するために,まず変敗飲料缶詰から変敗原因菌の分離を試みた結果,至適発育pHが4.0-4.5にあり中性付近では発育できない好酸性菌が新たに分離でき,Bergey's manual of systematic bacteriologyに準拠して同定するとBacillus属に分類された。しかしながら種レベルまで性状が一致するものの記載が認められなかったため,これら細菌の16SリボゾームRNA(rRNA)塩基配列をおよそ1500塩基決定し,DDBJ登録されている類縁菌種の16SrDNA塩基配列と比較した結果,Alicyclobacillus acidoterrestrisと92.5-93.0%,A.acidocardariusと92.3-92.8%のホモロジーを示し,これらの結果から本分離株はいずれもAlicyclobacillus属に分類されたが,種名までは明らかにできなかった。また本分離株とその類縁菌種との系統的関係を,近隣接続法(NJ法)を用いて推定した結果,Alicyclobacillus属と系統的に非常に近い関係にあったが,いずれの分離菌株ともこれまで報告されているAlicyclobacillus属とは異なるクラスターを形成した。これらのことから,本分離菌株が新種の可能性を有していると考えられた。
次に,低酸性飲料変敗原因菌の16SrRNA塩基配列から,迅速検出用プライマー部位を2カ所選定(190Fおよび490R)し,それらの特異性および感度について検討した。その結果,これらプライマーは非常に高い特異性を有しており,また少なくとも100agのDNAが存在すれば検出可能の範囲であることが確認できた。さらに現在,従来法とPCR法を用いた本手法との比較を行っており,平成6年度当初の計画はほぼ達成されたと考えている。
文部科学省, 奨励研究(A), 北海道大学, Competitive research funding, 06856026

The role of squid liver and ink on the formation of specific microflora of "Ika-Shiokara".
Grants-in-Aid for Scientific Research
1993 - 1994
SHINANO Haruo, YAMAZAKI Koji, KAWAI Yuji, INOUE Norio
The effect of various concentrations of the addition of squid liver and to "Ika-Shiokara" with 10% salt were examined on the changes of microflora and chemical prooeties of "Ika-Shiokara" and the inoculated pathogenic organism, Staphylococcus aureus.
In the case of the "Ika-Shokara" without the addition of squid liver, the dominant species of S.warneri found in the early stage (2-4days) were replaced by Micrococci in the later stage of ripening.In the case of the sample with 1% squid liver, the dominant microorganism was S.warneri in the early stage, and the Staphylococci including S.warneri were replaced by Micrococci during the later stage of ripening (4-14days).In the case, the quility of "Ika-Shiokara" was decreased with the shift of dominant Staphylococci to Micrococci.In the case of 3% liver addition, among the dominant Staphylococci over the ripening preocess, S.epidermidis were shown to predominated on the last day of sampling.The inoculated S.aurues decreased during the ripening process with the addition of aquid liver 3-6%.The squid ink had a particulaly strong effect, and elongated the period of edibility.
S.epidermidis has never been isolated from "Ika-Shiokara" with the addition of ink, and was therefore isolated without ink.In the in vitro experiments, both S.epidermidis and S.aureus were inhibited by the extracts of heated squid ink.These findings suggest that the addition of squid liver and ink plays important roles in the formation of specific microflora of " Ika-Shiokara", and there are heat stable inhibitory substances in the squid liver and ink.
Japan Society for the Promotion of Science, Grant-in-Aid for General Scientific Research (C), Hokkaido University, Competitive research funding, 05660223

培養併用インサイチューハイブリダイゼーション法により生きている緑膿菌を迅速かつ特異的に計数するための遺伝子プローブ及びその方法　　　　　　　　　　　　　　　
Patent right, 澤辺 智雄, 山崎浩司, 吉澤 愛
特願2007-109741, 14 Apr. 2007
特開2008-263829, 06 Nov. 2008
特許第5074084号
31 Aug. 2012

簡易迅速培養併用蛍光インサイチューハイブリダイゼーション法　　　　　　　　　　　　　　　
Patent right, 大坪 雅史, 山崎浩司, 澤辺 智雄, 荒磯 恒久, 浜出 雄一
特願2005-122391, 20 Apr. 2005
特開2006-296285, 02 Nov. 2006
特許第4950433号
16 Mar. 2012

培養併用インサイチューハイブリダイゼーション法により生きている食中毒細菌及び衛生指標細菌群を迅速かつ特異的に計数するための遺伝子プローブ及びその方法（ウエルシュ菌）　　　　　　　　　　　　　　　
Patent right, 山崎浩司, 澤辺智雄, 田島研一, 大坪雅史, 小松恵里子
特願2011-172169, 05 Aug. 2011
特開2011-224020, 10 Nov. 2011

培養併用インサイチューハイブリダイゼーション法により生きている食中毒細菌及び衛生指標細菌群を迅速かつ特異的に計数するための遺伝子プローブ及びその方法（リステリア）　　　　　　　　　　　　　　　
Patent right, 山崎浩司, 澤辺智雄, 田島研一, 大坪雅史, 小松恵里子
特願2011-172166, 05 Aug. 2011
特開2011-224019, 10 Nov. 2011

培養併用インサイチューハイブリダイゼーション法により生きている食中毒細菌及び衛生指標細菌群を迅速かつ特異的に計数するための遺伝子プローブ及びその方法（腸炎ビブリオ）　　　　　　　　　　　　　　　
Patent right, 山崎浩司, 澤辺智雄, 田島研一, 大坪雅史, 小松恵里子
特願2011-172174, 05 Aug. 2011
特開2011-212030, 27 Oct. 2011

培養併用ｉｎｓｉｔｕハイブリダイゼーション法により生きているカンピロバクター菌を迅速かつ特異的に計数するための遺伝子プローブ及びその方法　　　　　　　　　　　　　　　
Patent right, 澤辺 智雄, 山崎浩司, 吉澤 愛, 大坪雅史
特願2008-191252, 24 Jul. 2008
特開2010-22336, 04 Feb. 2010

培養併用インサイチューハイブリダイゼーション法により生きている食中毒細菌及び衛生指標細菌群を迅速かつ特異的に計数するための遺伝子プローブ及びその方法　　　　　　　　　　　　　　　
Patent right, 山崎浩司, 澤辺智雄, 田島 研一, 大坪 雅史, 小松 恵里子
特願2005-336201, 29 Jun. 2006
特開2006-166912, 21 Nov. 2005

抗菌組成物、及び、魚病類結節症の予防剤及び／又は治療剤　　　　　　　　　　　　　　　
Patent right, 猪上徳雄, 川合祐史, 山崎浩司, 栗原秀幸, 熊谷光倫, 澤野 亮
特願2004-105563, 31 Mar. 2004
特開2005-289858, 20 Oct. 2005