Researcher Profile and Settings

Master

Affiliation (Master)

• Research Faculty of Agriculture　Fundamental AgriScience Research　Forest Science

Affiliation (Master)

• Research Faculty of Agriculture　Fundamental AgriScience Research　Forest Science

researchmap

Profile and Settings

Degree

• (BLANK)

Profile and Settings

• Name (Japanese)

  Tamai

• Name (Kana)

  Yutaka

• Name

  200901004962562900

Alternate Names

http://www.agr.hokudai.ac.jp/fres/fbio/

Achievement

Research Areas

• Environmental science/Agricultural science / Landscape science
• Environmental science/Agricultural science / Environmental agriculture
• Life sciences / Wood science
• Life sciences / Forest science
• Life sciences / Applied biochemistry

Awards

• 1996 大蔵省印刷局朝陽会賞
  
• 1996 日本紙パルプ技術協会賞
  

Published Papers

• Ectomycorrhizal Fungal Communities Associated with Dominant Tree Species in a Subarctic Limestone Area

  Hirotaka Mori, Keisuke Obase, Takashi Yajima, Toshizumi Miyamoto, Yutaka Tamai

  Asian Soil Research Journal 7 (2) 34 - 45 2023/05/13 

  Limestone soils are stressful for plant growth. Plant-associated ectomycorrhizal (ECM) fungi may promote plant growth under stressful conditions, yet available information on ECM fungi in limestone areas is scarce. We investigated the ECM fungal communities associated with dominant tree species in a subarctic limestone area. We aimed to determine whether the ECM species differed between calcareous and non-calcareous areas, and the distribution property common to ECM fungi in limestone areas. Morphological characterization and DNA sequencing of root tips identified 57 ECM taxa. The ECM fungal compositions in the calcareous area differed from those in the non-calcareous area, even when comparisons were made between fungi on the same tree species. Rather, when ECM species were grouped at the genus level, they tended to be dissimilar between calcareous areas and between non-calcareous areas. Especially, Tomentella spp. and Sebacina spp. tended to be present more frequently in calcareous areas, while Cenococcum geophilum and Russula spp. tended to be present more frequently in non-calcareous areas.
• Single and combined effects of fertilization, ectomycorrhizal inoculation, and drought on container-grown Japanese larch seedlings

  Evgenios Agathokleous, Mitsutoshi Kitao, Masabumi Komatsu, Yutaka Tamai, Hisanori Harayama, Takayoshi Koike

  Journal of Forestry Research doi.org/10.1007/s11676-022-01565-3  1007-662X 2022/11/12 [Refereed]
   

  Abstract Climate change can intensify drought in many regions of the world and lead to more frequent drought events or altered cycles of soil water status. Therefore, it is important to enhance the tolerance to drought and thus health, vigor, and success of transplantation seedlings used in the forestry by modifying fertilization and promoting mycorrhization. Here, we sowed seeds of Japanese larch (Larix kaempferi) in 0.2-L containers with 0.5 g (low fertilization; LF) or 2 g (high fertilization; HF) of slow-release fertilizer early in the growing season. One month later, we irrigated seedlings with non-sterilized ectomycorrhizal inoculum (ECM) or sterilized solution (non-ECM), and after about 2 months, plants were either kept well watered (WW; 500 mL water/plant/week) or subjected to drought (DR; 50 mL water per plant/week) until the end of the growing season. HF largely stimulated plant growth and above- and belowground biomass production, effects that are of practical significance, but caused a small decrease in stomatal conductance (Gs₃₉₀) and transpiration rate (E₃₉₀), which in practice is insignificant. ECM treatment resulted in moderate inhibition of seedling growth and biomass and largely canceled out the enhancement of biomass and foliar K content by HF. DR caused a large decrease in CO₂ assimilation, and enhanced stomatal closure and induced senescence. DR also largely depleted foliar Mg and enriched foliar K. Although DR caused a large decrease in foliar P content in LF, it moderately increased P in HF. Likewise, DR increased foliar K in HF but not in LF, and decreased foliar P in ECM plants but not in non-ECM plants. Conversely, ECM plants exhibited a large enrichement in foliar P under WW and had a lower water potential under DR when grown in LF. These results indicate that the drought tolerance and health and vigor of Japanese larch seedlings can be modified by soil fertility and soil microorganisms. This study provides a basis for new multifactorial research programs aimed at producing seedlings of superior quality for forestation under climate change.
• Responses of ectomycorrhizal diversity of larch and its hybrid seedlings and saplings to elevated CO2, O3, and high nitrogen loadin

  QU, Laiye, WANG, Xiaona, MAO, Qiaozhi, AGATHOKLEOUS, Evgenios, CHOI, DongSu, TAMAI, Yutaka, WATANABE, Toshihiro, KOIKE

  Eurasian Journal of Forest Research 22 23 - 27 2022/05 [Refereed][Invited]
  
• Phylogenetic placements and cultural characteristics of Tuber species isolated from ectomycorrhizas

  Keisuke Obase, Satoshi Yamanaka, Akihiko Kinoshita, Yutaka Tamai, Takashi Yamanaka

  Mycoscience 62 (2) 124 - 131 1340-3540 2021/03/20 [Refereed]
   

  Pure cultures of Tuber were isolated from ectomycorrhizal root tips in Abies sachalinensis plantations in Hokkaido, Japan. Their phylogenetic relationships as well as vegetative hyphal characteristics on culture media were reported. Phylogenetic analysis based on the internal transcribed spacer within ribosomal DNA settled well-supported eight lineages within Puberulum, Latisporum, and Maculatum clades in Tuber. Three and one lineages were grouped with undescribed species of Puberulum Glade in Japan and that of the Latisporum group in China, respectively. Two lineages were closely associated to but distinct from an undescribed species of Puberulum Glade in Japan. One lineage did not group with any sequences in the International Nucleotide Sequence Database (INSD), proposing a new taxon in the Latisporum group. One lineage was grouped with T. foetidum in Maculatum Glade. All strains in each lineage displayed yellowish white, thin, filamentous colonies on Melin-Norkrans agar medium. Various differences in morphological characteristics of hyphae on pure cultures of various strains were noted, but they were frequently uncommon among strains of the same taxa. Isolation from ectomycorrhizal root tips can be among the effective ways to acquire pure cultures of Tuber strains.
• Effects of soil nutrient availability and ozone on container-grown Japanese larch seedlings and role of soil microbes

  Evgenios Agathokleous, Mitsutoshi Kitao, Masabumi Komatsu, Yutaka Tamai, Hideyuki Saito, Hisanori Harayama, Akira Uemura, Hiroyuki Tobita, Takayoshi Koike

  Journal of Forestry Research 31 (6) 2295 - 2311 1007-662X 2020/12 [Refereed]
   

  The interactive effects of ozone, soil nutrient availability and root microorganisms on physiological, growth, and productivity traits were studied for the first time for Japanese larch (Larix kaempferi) seedlings grown in containers over a growing season, using a free air ozone-concentration enrichment exposure system. High nutrient availability altered leaf and root nutrient dynamics and enhanced plant growth; however, it also enhanced seedling susceptibility to damping-off disease compared to low nutrient availability. Negative effects of elevated ozone, as compared with ambient ozone, on leaf gas exchange and plant stem form were neither offset nor exacerbated by soil nutrient availability and root colonizers. Such negative effects suggest that elevated ozone may have implications for ecological health even when plant vigor is limited by factors other than ozone. Inoculation of roots with ectomycorrhizae had negligible influence on the effects of either soil nutrient availability or ozone. However, this lack of effect may be upon impeded formation of complete mycorrhizal root tips due to factors other than the manipulated variables. B and Na appeared to have an important role in stress responses, so further studies to examine their link with physiological mechanisms as a function of time. This study provides an important perspective for designing forestry practices to enhance seedling health.
• 2000年に噴火した有珠山の噴出物堆積地における大型菌類の発生消長

  小長谷啓介, 宮本敏澄, 玉井 裕, 矢島 崇

  日本菌学会会報 61 (2) 81 - 90 2020/11 [Refereed]
  
• Evaluating Soil–Root Interaction of Hybrid Larch Seedlings Planted under Soil Compaction and Nitrogen Loading

  Tetsuto Sugai, Satoko Yokoyama, Yutaka Tamai, Hirotaka Mori, Enrico Marchi, Toshihiro Watanabe, Fuyuki Satoh, Takayoshi Koike

  Forests 11 (9) 947 - 947 2020/08/29 [Refereed]
   

  Although compacted soil can be recovered through root development of planted seedlings, the relationship between root morphologies and soil physical properties remain unclear. We investigated the impacts of soil compaction on planted hybrid larch F1 (Larix gmelinii var. japonica×L. kaempferi, hereafter F1) seedlings with/without N loading. We assumed that N loading might increase the fine root proportion of F1 seedlings under soil compaction, resulting in less effects of root development on soil recovery. We established experimental site with different levels of soil compaction and N loading, where two-year-old F1 seedlings were planted. We used a hardness change index (HCI) to quantify a degree of soil hardness change at each depth. We evaluated root morphological responses to soil compaction and N loading, focusing on ectomycorrhizal symbiosis. High soil hardness reduced the total dry mass of F1 seedlings by more than 30%. Significant positive correlations were found between HCI and root proportion, which indicated that F1 seedling could enhance soil recovery via root development. The reduction of fine root density and its proportion due to soil compaction was observed, while these responses were contrasting under N loading. Nevertheless, the relationships between HCI and root proportion were not changed by N loading. The relative abundance of the larch-specific ectomycorrhizal fungi under soil compaction was increased by N loading. We concluded that the root development of F1 seedling accelerates soil recovery, where N loading could induce root morphological changes under soil compaction, resulting in the persistent relationship between root development and soil recovery.
• Effects of biochar and litter on water relations of Japanese black pine (Pinus thunbergii) seedlings

  Saki Fujita, Hanami Watanabe, Vitas Marozas, Yutaka Tamai, Fuyuki Satoh, Takayoshi Koike

  Journal of Forest Research 25 (2) 76 - 82 1341-6979 2020/03/03 [Refereed]
  
• Comparison of Mycelial Growth of Different Tricholoma matsutake Strains in Soil Medium at Varying Temperatures

  Maki Narimatsu, Muneyoshi Yamaguchi, Takashi Yamanaka, Seiki Gisusi, Tomonori Azuma, Yutaka Tamai, Tohru Fujita, Masataka Kawai

  Asian Journal of Biotechnology and Bioresource Technology Sciencedomain International 5 1 - 8 2019/11/20 [Refereed]
   

  Aims: To investigate the effect of temperature on the mycelial growth of the highly prized mushroom, Tricholoma matsutake, in soil medium. Methodology: Seven strains of T. matsutake collected from different areas of Japan were incubated in soil medium at 5, 10, 15, 20, 25, and 30°C for 89 day. After incubation, the linear growth of mycelia from the inoculum was measured on vertical lines under a dissecting microscope and classified by the cultivation day number to obtain the growth rate in each vial. The mycelial densities in the soil medium in all the vials were analyzed using qPCR to determine the mycelial biomass. Results: The mycelial growth of T. matsutake strains was mainly observed at 5–25°C. The optimum temperatures for linear mycelial growth and for the increase in mycelial density were 19.6°C and 17.6°C, respectively. These values were lower than those reported previously for T. matsutake grown on agar medium or in liquid medium. These optimum temperatures showed no clear relationship with the mean air temperature at the site of strain collection. Conclusion: It can be suggested that a temperature around 18°C is suitable for cultivation of T. matsutake mycelia in the soil medium.
• Investigation of soil environments in the vicinity of Tricholoma matsutake mycelium in Abies sachalinensis stands

  GISUSI Seiki, AZUMA Tomonori, YOSHIDA Shigeichi, YONEYAMA Shozo, HARADA Akira, TSUDA Mayumi, TAMAI Yutaka

  Japanese Journal of Mycology 日本菌学会 60 (2) 43 - 48 0029-0289 2019/11 [Refereed]
   

  To understand the habitat of Tricholoma matsutake in Hokkaido, we investigated the soil environment in an Abies sachalinensis plantation where this fungus colonized. As a result, soil pH and microbial quantity (colony forming unit; cfu) showed lower trend around the colony of T. matsutake than those areas where this fungus was not colonized. In addition, soil temperature was maintained over 0℃ even in the mid-winter despite the minimum air temperature recoded below −20℃, due to snow cover on the forest floor.
• Comparison of the Ability of Several White-rot Fungi to Biobleach Acacia Oxygen-delignified Kraft Pulp

  Sitompul Afrida, Toshihiro Watanabe, Yutaka Tamai

  Asian Journal of Biotechnology and Bioresource Technology 5 (3) 1 - 10 2019/10/15 [Refereed]
   

  Previous screening analyses demonstrated that the in vivo biobleaching activities of the white-rot fungi Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 are higher than those of Phanerochaete chrysosporium and Trametes versicolor. The purpose of the current study was to examine the production of extracellular enzymes of these four white-rot fungi grown on three types of low-cost media containing agricultural and forestry waste, and to evaluate the ability of the produced extracellular enzymes to biobleach Acacia oxygen-delignified kraft pulp (A-OKP). The biobleaching activity of extracellular fractions of I. lacteus, L. tigrinus, T. versicolor, and P. chrysosporium cultures was the most pronounced after 3 days of incubation with Acacia mangium wood powder supplemented with rice bran and 1% glucose (WRBG) with resultant Kappa number reduction of 4.4%, 6.7%, 3.3%, and 3.3%, respectively. Therefore, biobleaching ability of I. lacteus and L. tigrinus have been shown to be higher than of T. versicolor and P. chrysosporium, both in vivo and in vitro.
• Use of DNA sequence data to identify wood-decay fungi likely associated with stem failure caused by windthrow in urban trees during a typhoon

  Yoshie Fukui, Toshizumi Miyamoto, Yutaka Tamai, Akio Koizumi, Takashi Yajima

  Trees 32 (4) 1147 - 1156 0931-1890 2018/08 [Refereed]
  
• Effects of simulated nitrogen deposition on ectomycorrhizae community structure in hybrid larch and its parents grown in volcanic ash soil: The role of phosphorous

  Xiaona Wang, Evgenios Agathokleous, Laiye Qu, Saki Fujita, Makoto Watanabe, Yutaka Tamai, Qiaozhi Mao, Akihiro Koyama, Takayoshi Koike

  Science of The Total Environment 618 905 - 915 0048-9697 2018/03 [Refereed]
  
• Changes in the Secondary Xylem of the Living Stem of Four Tree Species in Response to Inoculation with Perenniporia fraxinea

  Mikio Ueta, Chiaki Hori, Yutaka Tamai, Yusuke Yamagishi, Toshizumi Miyamoto, Yuzou Sano

  Mokuzai Gakkaishi 64 (1) 1 - 9 0021-4795 2018 [Refereed][Not invited]
   

  This study aimed to clarify the factors that influence tree susceptibility to infection by the white-rot fungus Perenniporia fraxinea, by inoculating it into stems of four tree species at butt and breast height, and comparing the alterations in the xylem three to five months after inoculation. The four tree species include Robinia pseudoacacia, Cerasus sargentii, Ulmus davidiana var. japonica and Picea glehnii; the former two species are easily infected by this fungus, whereas the latter two species are not. Polymerase chain reaction (PCR) analysis detected the inoculated fungus only in the butt xylem of R. pseudoacacia and C. sargentii and the cell walls in the butt xylem tissues of these species were eroded by hyphae. Other xylem alterations (e.g., water accumulation and cell occlusion) differed among tree species, whereas no apparent difference was observed between butt and breast height. For example, water accumulation occurred in the discolored wood tissues around the inoculated holes in both R. pseudoacacia and U davidiana var. japonica, while dehydration occurred in the light-colored wood tissues around the inoculated hole in P. glehnii. In the vicinity of the inoculation holes, resin deposits formed in P. glehnii, whereas cell occlusions by tyloses/gums occurred in the other three species. These results suggest that susceptibility to P. fraxinea infection differs not only among tree species but also between heights above ground. It is likely that no particular response to fungal inoculation in the xylem tissues of these four tree species is closely associated with their susceptibility to the infection by P. fraxinea.
• A pronounced improvement of the kappa number reduction and pulp properties associated with the use of extracellular enzymes secreted by selected fungal strains

  Sitompul Afrida, Toshihiro Watanabe, Yutaka Tamai

  BioResources 12 (4) 8272 - 8285 1930-2126 2017/11/01 

  A combination of extracellular enzymes secreted by Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 showed promising results in the reduction of kappa number of Acacia oxygen-delignified kraft pulp (A-OKP) in previous studies. However, the observed Kappa number reduction was low, and the bleaching process required further optimization. In the current study, the A-OKP was treated with a combination of extracellular enzymes of I. lacteus and L. tigrinus, with a subsequent alkaline peroxide extraction, which significantly improved the Kappa number reduction. The maximum achieved Kappa number reduction was 26%. The effects of static incubation and sterilization of the extracellular enzymes on biobleaching process were evaluated. Compared with a static biobleaching, biobleaching with shaking shortened the required incubation time required from 3 to 1 d. The utility of extracellular enzymes was tested with and without sterilization no significant differences in Kappa number reduction, brightness, and physical properties of the pulp were observed. The physical properties of all pulp samples were improved following the enzymatic treatment. Furthermore, a low-cost medium containing wood powder supplemented with rice bran and palm sugar (WRBP) was used for the production of enzymes for biobleaching of A-OKP.
• Optimization of simultaneous saccharification and fermentation conditions with amphipathic lignin derivatives for concentrated bioethanol production

  Ningning Cheng, Keiichi Koda, Yutaka Tamai, Yoko Yamamoto, Taichi E. Takasuka, Yasumitsu Uraki

  BIORESOURCE TECHNOLOGY 232 126 - 132 0960-8524 2017/05 [Refereed][Not invited]
   

  Amphipathic lignin derivatives (A-LDs) prepared from the black liquor of soda pulping of Japanese cedar are strong accelerators for bioethanol production under a fed-batch simultaneous enzymatic saccharification and fermentation (SSF) process. To improve the bioethanol production concentration, conditions such as reaction temperature, stirring program, and A-LDs loadings were optimized in both small scale and large scale fed-batch SSF. The fed-batch SSF in the presence of 3.0 g/L A-LDs at 38 degrees C gave the maximum ethanol production and a high enzyme recovery rate. Furthermore, a jar-fermenter equipped with a powerful mechanical stirrer was designed for 1.5 L-scale fed-batch SSF to achieve rigorous mixing during high substrate loading. Finally, the 1.5 L fed-batch SSF with a substrate loading of 30% (w/v) produced a high ethanol concentration of 87.9 g/L in the presence of A-LDs under optimized conditions. (C) 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
• Association of amphipathic lignin derivatives with cellobiohydrolase groups improves enzymatic saccharification of lignocellulosics

  Yoko Yamamoto, Ningning Cheng, Keiichi Koda, Kiyohiko Igarashi, Yutaka Tamai, Yasumitsu Uraki

  CELLULOSE 24 (4) 1849 - 1862 0969-0239 2017/04 [Refereed][Not invited]
   

  Amphipathic lignin derivatives (ALDs), prepared from hardwood acetic acid lignin and softwood soda lignin via coupling with a mono-epoxylated polyethylene glycol, have been reported to improve the enzymatic saccharification efficiency of lignocellulose while maintaining significant residual cellulase activity after saccharification. We previously demonstrated that the effect of ALDs was caused by a direct interaction between ALDs and Cel6A (or CBH II). In this study, a different ALD was prepared from softwood kraft lignin in addition to aforementioned ALDs. The interactions between all the ALDs and the enzymes other than Cel6A, such as Cel7A and Cel7B, in a cellulase cocktail were investigated using surface plasmon resonance. The kraft lignin-based ALD showed the highest residual cellulase activity among all ALDs and an improved cellulolytic enzyme efficiency similar to those of the other ALDs. All ALDs were found to directly associate with major enzymes in the cellulase cocktail, Cel6A and Cel7A (or CBH I), but not with Cel7B (or EG I). In addition, the ALDs showed a much higher affinity to amino groups than to hydroxy and carboxy groups. In contrast, polyethylene glycol (molecular mass 4000 Da), one part of the ALD and a previously reported enzymatic saccharification enhancer, did not adsorb onto any enzymes in the cellulase cocktail or the amino group. Size exclusion chromatography demonstrated that the ALDs formed self-aggregates in both water and chloroform; the formation process in the latter was especially unique. Therefore, we conclude that the high residual cellulase activity is attributed to the direct association of ALD aggregates with the CBH group.
• Ectomycorrhizal fungal communities associated with Quercus dentata in a coastal broadleaf forest

  H. Arai, Y. Tamai, T. Yajima, K. Obase, T. Miyamoto

  MYCOSPHERE 8 (4) 561 - 567 2077-7000 2017 [Refereed][Not invited]
   

  Coastal forests are exposed to high salinity and drought stress, and plant growth is restricted under such harsh conditions. Quercus dentata is one of the most common species in coastal forests in northern Japan. We investigated the changing vegetation in a coastal forest, shoreline to inland, and examined the ectomycorrhizal (ECM) fungal communities associated with Q. dentata. We aimed to determine whether the ECM changes corresponded with the changes in vegetation. More than 300 m inland, broadleaf trees such as Q. dentata were dominant. An almost pure Q. dentata stand was formed in the area closest to the shoreline. By contrast, as the forest moved inland, the occurrence of other tree species increased and the density of Q. dentata gradually decreased, respectively. In the areas that were furthest inland, Q. dentata, Q. crispula, Acer mono, and Tilia japonica were equally dominant. Five sampling plots (20 m x 20 m, each) were set up in the forest 100 m apart, and soil cores (including the fine roots of Q. dentata) were sampled in each plot. The total ECM colonization rate was > 98% in each sampling plot. Morphological characterization and DNA sequencing of the root tips identified six taxa (Tomentella sp., Russula spp., Tricholoma sp., Hebeloma sp. and Boletales sp.). Tomentella sp. was relatively abundant near the shoreline and its abundance decreased as the density of Q. dentata decreased inland. Conversely, Russula sp. increased as the forest moved inland.
• Ectomycorrhizal colonization and growth of the hybrid larch F-1 under elevated CO2 and O-3

  Xiaona Wang, Laiye Qu, Qiaozhi Mao, Makoto Watanabe, Yasutomo Hoshika, Akihiro Koyama, Korin Kawaguchi, Yutaka Tamai, Takayoshi Koike

  ENVIRONMENTAL POLLUTION 197 116 - 126 0269-7491 2015/02 [Not refereed][Not invited]
   

  We studied the colonization of ectomycorrhizal fungi and species abundance of a hybrid larch (F-1) under elevated CO2 and O-3. Two-year-old seedlings were planted in an Open-Top-Chamber system with treatments: Control (O-3 < 6 nmol/mol), O-3 (60 nmol/mol), CO2 (600 mu mol/mol), and CO2 + O-3. After two growing seasons, ectomycorrhiza (ECM) colonization and root biomass increased under elevated CO2. Additionally, O-3 impaired ECM colonization and species richness, and reduced stem biomass. However, there was no clear inhibition of photosynthetic capacity by O-3. Concentrations of Al, Fe, Mo, and P in needles were reduced by O-3, while K and Mg in the roots increased. This might explain the distinct change in ECM colonization rate and diversity. No effects of combined fumigation were observed in any parameters except the P concentration in needles. The tolerance of F-1 to O-3 might potentially be related to a shift in ECM community structure. (C) 2014 Elsevier Ltd. All rights reserved.
• Effect of charcoal and fallen-leaves of black locust on water relations of black pine seedlings

  Watanabe Hanami, Fujita Saki, Meng Fakeng, Tamai Yutaka, Saito Hideyuki, shibuya Masato, Koike Takayoshi

  The Japanese Forest Society Congress 日本森林学会 126 (0) 255 - 255 2015 [Refereed][Not invited]
   

  [in Japanese]
• Amphipathic lignin derivatives to accelerate simultaneous saccharification and fermentation of unbleached softwood pulp for bioethanol production

  Ningning Cheng, Yoko Yamamoto, Keiichi Koda, Yutaka Tamai, Yasumitsu Uraki

  BIORESOURCE TECHNOLOGY 173 104 - 109 0960-8524 2014/12 [Refereed][Not invited]
   

  Amphipathic lignin derivatives (A-LDs) were already demonstrated to improve enzymatic saccharification of lignocellulose. Based on this knowledge, two kinds of A-LDs prepared from black liquor of soda pulping of Japanese cedar were applied to a fed-batch simultaneous saccharification and fermentation (SSF) process for unbleached soda pulp of Japanese cedar to produce bioethanol. Both lignin derivatives slightly accelerated yeast fermentation of glucose but not inhibited it. In addition, ethanol yields based on the theoretical maximum ethanol production in the fed-batch SSF process was increased from 49% without A-LDs to 64% in the presence of A-LDs. (C) 2014 Elsevier Ltd. All rights reserved.
• Biobleaching of Acacia kraft pulp with extracellular enzymes secreted by Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 using low-cost media

  Sitompul Afrida, Yutaka Tamai, Toshihiro Watanabe, Mitsuru Osaki

  WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY 30 (8) 2263 - 2271 0959-3993 2014/08 [Refereed][Not invited]
   

  The white-rot fungi Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 have been shown in previous studies to have high biobleaching activity in vivo. The aim of this study was to investigate the activities and stabilities of extracellular enzymes, prepared from I. lacteus and L. tigrinus culture grown in three types of economical media of agricultural and forestry wastes, for biobleaching of Acacia oxygen-delignified kraft pulp using kappa number reduction as an indicator of delignification. After 3 days of incubation, the extracellular enzymes preparations from I. lacteus and L. tigrinus cultures in media of Acacia mangium wood powder supplemented with rice bran and addition 1 % glucose (WRBG), resulted in significant decrease of 4.4 and 6.7 %, respectively. A slightly higher kappa number reduction (7.4 %) was achieved with the combine extracellular enzymes from I. lacteus and L. tigrinus. One of the strategies for reducing the cost of enzyme production for treatment processes in the pulp and paper industry is the utilization of agricultural and forestry waste. Thus, WRBG has potential as a culture medium for producing stable lignolytic enzymes simply and economically.
• Relationship between intraspecific variations and host insects of Ophiocordyceps nutans collected in Japan

  Fumito Sasaki, Toshizumi Miyamoto, Aki Yamamoto, Yutaka Tamai, Takashi Yajima

  MYCOSCIENCE 53 (2) 85 - 91 1340-3540 2012/03 

  To investigate the host specificity of Ophiocordyceps nutans against hemipteran insects in the wild, we determined the relationship between host species and rDNA-internal transcribed spacer (ITS) variation in O. nutans. The analyzed fungal specimens infected 16 host species belonging to four families of Hemiptera. The molecular phylogenetic analysis revealed that O. nutans can be classified into two types corresponding to their host families. The genetic distance values between the two types were very remote (> 0.084), and the strains of O. nutans that parasitized Halyomorpha halys and Plautia crossota stali, well-known insect pests, formed a subclade. The results suggest that O. nutans should have host specificity which can be valuable for developing biological control agents against specific hemipteran insects.
• Fabrication of honeycomb-patterned cellulose material that mimics wood cell wall formation processes

  Yasumitsu Uraki, Yutaka Tamai, Takuro Hirai, Keiichi Koda, Hiroshi Yabu, Masatsugu Shimomura

  MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS 31 (6) 1201 - 1208 0928-4931 2011/08 [Refereed][Not invited]
   

  Wood cell wall, composed of polysaccharides (cellulose and hemicelluloses) and an aromatic polymer (lignin), exhibits a honeycomb-like alignment. We have been making attempts to fabricate cellulose-based materials to reconstruct these wood components artificially, mimicking their formation processes. Those attempts are aiming not only at better understanding of the significance and the function of each wood component, but also at providing a novel, biomass-based polymer material with functionality. This article outlines a protocol to prepare honeycomb-patterned cellulose films with two different polymorphisms, carrying different pore sizes, as a basic framework of the artificial cell wall structure. It also illustrates the effect of the presence of hemicellulose and lignin on the physical property of the honeycomb-patterned cellulose films, when they were adsorbed onto the films. (C) 2010 Elsevier B.V. All rights reserved.
• Ectomycorrhizal fungi promote growth of Shorea balangeran in degraded peat swamp forests

  Maman Turjaman, Erdy Santoso, Agung Susanto, Sampang Gaman, Suwido H. Limin, Yutaka Tamai, Mitsuru Osaki, Keitaro Tawaraya

  WETLANDS ECOLOGY AND MANAGEMENT 19 (4) 331 - 339 0923-4861 2011/08 

  Shorea balangeran is an important component of peat swamp forests in Southeast Asia and is an important source of timber. However, S. balangeran has been decreasing in number due to overexploitation. The objective of this study was to investigate the effect of inoculation of native ectomycorrhizal (ECM) fungi on growth of S. balangeran in degraded peat swamp forest. Spores of Boletus sp., Scleroderma sp., and Strobilomyces sp. were collected from natural peat swamp forest in Indonesia. Seedlings of S. balangeran were inoculated with or without (control) spores and grown in sterilized peat soil under nursery conditions for 6 months. Then, the seedlings were transplanted into a degraded peat swamp forest and grown for 40 months. ECM colonization was 59-67% under nursery conditions and increased shoot height and weight. Shoot height, stem diameter, and survival rates were higher in inoculated seedlings than in control 40 months after transplantation. The results suggest that inoculation of native ECM fungi onto native tree species is useful for reforestation of degraded peat swamp forests.
• Screening of white rot fungi for biobleaching of Acacia oxygen-delignified kraft pulp

  Sitompul Afrida, Yutaka Tamai, Toshihiro Watanabe, Mitsuru Osaki

  WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY 25 (4) 639 - 647 0959-3993 2009/04 [Refereed][Not invited]
   

  To reduce the levels of chlorine-based chemicals in Acacia kraft pulp, we sought to isolate white rot fungus strains that could be used for biobleaching. For this purpose, we collected 600 fungal sources from Indonesia and subjected them to a three-step screening method. The first step involved culturing the strains on Acacia mangium wood powder, guaiacol and agar (WGA) medium. Of the 600 sources, 258 strains grew on WGA medium and generated a red color. The second step revealed that 31 of the 258 strains could degrade extractive-free A. mangium wood powder. The third step examined the ability of the strains to bleach A. mangium oxygen-delignified kraft pulp (A-OKP) under various pH conditions and showed that five strains could biobleach A-OKP at pH 5, 6, and 8. In contrast, the biobleaching abilities of Trametes versicolor and Phanerochaete chrysosporium, which served as standards, were much lower than those of the five new strains, particularly at pH 8. These five strains may be useful for biobleaching of A-OKP.
• Mycorrhizal synthesis of four ectomycorrhizal fungi in potted Populus maximowiczii seedlings

  Keisuke Obase, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto

  MYCOSCIENCE 50 (2) 143 - 145 1340-3540 2009/03 [Refereed][Not invited]
   

  Ectomycorrhizal (ECM) syntheses between four ECM fungi, Laccaria amethystina, Hebeloma mesophaeum, Thelephora terrestris, and Tomentella sp., and Populus maximowiczii seedlings that are known to form ECM at a denuded area of Mt. Usu were performed in volcanic debris in a controlled growth chamber. The percentage of ECM colonization and seedling growth were determined 3 months after inoculation. Seedlings were successfully colonized by the inoculated ECM fungi with low contamination ratios. Seedling height and biomass were larger in the inoculated seedlings than in the control, although the effects of inoculation on seedling growth varied with the ECM fungus.
• Morphological and genetic characteristics of the entomopathogenic fungus Ophiocordyceps nutans and its host insects

  Fumito Sasaki, Toshizumi Miyamoto, Aki Yamamoto, Yutaka Tamai, Takashi Yajima

  MYCOLOGICAL RESEARCH 112 1241 - 1244 0953-7562 2008/10 [Refereed][Not invited]
   

  We examined the morphology, genetic variation, and insect host species of the fungus Ophiocordyceps nutans. Fifty-two fruit bodies collected in Hokkaido, Japan, were grouped by host species, and 19 samples were analysed. The ranges of the lengths and breadths of all fruit body parts were similar among host groups. In the genetic analysis, the 5.8S rDNA region showed completely identical sequences, although differences of up to six nucleotides were recognized in the ITS regions. The distance values between our samples using the Kimura two-parameter model were lower than 0.007. Thus, the O. nutans examined here were concluded to form a closely related group with little detectable variability that parasitized nine hemipteran species. (c) 2008 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
• Mycorrhizal colonization status of plant species established in an exposed area following the 2000 eruption of Mt. Usu, Hokkaido, Japan

  Keisuke Obase, Yutaka Tamai, Takashi Yajima, Toshizumi Miyamoto

  LANDSCAPE AND ECOLOGICAL ENGINEERING 4 (1) 57 - 61 1860-1871 2008/05 [Refereed][Not invited]
   

  We investigated the ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) colonization status of plant seedlings that established in areas devastated by the eruption in March 2000 of Mt. Usu, Hokkaido, Japan. In 2005, we estimated the mycorrhizal colonization ratios and frequencies in seedlings of twelve herbaceous and seven woody plant species. Although arbuscular mycorrhizas were found to colonize Equisetum arvense and Polygonum sachalinense, they were presented at very low frequencies and colonization ratios. Other herbaceous plants exhibited higher frequencies of AM associations and either AM and/or ECM fungal associations were observed in all of the woody plant seedlings investigated. The dominant woody plant species (Populus maximowiczii, Salix sachalinensis and Salix hultenii var. angustifolia) associated mainly with ECM fungi and exhibited variable associations with AM fungi. Mycorrhizal associations were common and significant events for plant establishment, even in the early stages of the revegetation process.
• The molecular phylogeny and design of specific PCR primers of Cordyceps nutans

  SASAKI FUMITO, TAMAI YUTAKA, YAMAMOTO AKI, MIYAMOTO TOSHIZUMI, YAJIMA TAKASHI

  Abstracts of Papers Presented at the Meeting of the Mycological Society of Japan 日本菌学会 52 103 - 103 2008 

  Cordyceps nutans Pat.はカメムシ類にのみ寄生を行なうとされている冬虫夏草菌であるが，寄生されるカメムシ類の種についての報告は少なく，カメムシ目レベル以下の寄主特異性に関しては全く明らかにされていない．本研究ではC. nutansのrDNA-ITS領域の変異と寄主の種との関連性の検討を行なった．さらに，得られた結果に基づき，C. nutans特異的PCRプライマーを設計した．北海道苫小牧および江別，山形，福島，京都，鹿児島より採取された56系統のC. nutansを供試し，各子実体の寄主となっていたカメムシの種を同定した．プライマーセットITS1fおよびITS4を用いて5.8S rDNAを含むITS領域をシーケンシングし，得られた配列についてKimura 2-parameter modelにより遺伝的距離を算出後，近隣結合法で系統樹を作成した．さらにシーケンスで得た他種の昆虫病原性糸状菌の同領域配列を参照し，C. nutansに特異的な配列部分よりプライマーの設計を行なった．56系統のC. nutansの寄主となっていたカメムシ類は4科10属15種に分類された．系統樹には遺伝的距離が0.090以上離れた二つのクレードが形成された．各クレードでC. nutansの寄主は異なり，片側のクレードに属するC. nutansはヘリカメムシ科カメムシに選択的に寄生を行ない (Type 1)，他方のクレードに属するC. nutansはその他の科のカメムシに寄生を行なっていた (Type 2)．ヘリカメムシ科カメムシは，主に草本植物の茎より吸汁を行なう草地性のカメムシであり，Type 2の寄主となる樹上で生活を行なうことの多いカメムシとはハビタットや吸汁対象がやや異なる．この結果から，ITS領域内にType 2にのみアニーリングサイトを持つフォワードプライマーと，両タイプにアニーリングサイトを持つリバースプライマーを作成し，その選択性を確認した．
• Mycorrhizal associations in woody plant species at the Mt. Usu volcano, Japan.

  Obase Keisuke, Tamai Yutaka, Yajima Takashi, Miyamoto Toshizumi

  Mycorrhiza Springer Berlin / Heidelberg 17 (3) 209 - 215 0940-6360 2007/05 

  We investigated the association between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi and pioneer woody plant species in areas devastated by the eruption of Mt. Usu, Japan, in 2000. We observed eight woody plant species at the research site, most of which were associated with ECM and/or AM fungi. In particular, dominant woody plant species Populus maximowiczii, Salix hultenii var. angustifolia and Salix sachalinensis were consistently associated with ECM fungi and erratically associated with AM fungi. We found one to six morphotypes in the roots of each ECM host and, on average, two in the roots of each seedling, indicating low ECM fungal diversity. ECM colonization ranged from 17 to 42% of root tips. Using morphotyping and molecular analyses, 15 ECM fungi were identified. ECM fungi differed greatly between hosts. However, Laccaria amethystea, Hebeloma mesophaeum, Thelephora terrestris and other Thelephoraceae had high relative colonization, constituting the majority of the ECM colonization in the roots of each plant species. These ECM fungi may be important for the establishment of pioneer woody plant species and further revegetation at Mt. Usu volcano.
• The effect of pioneer ectomycorrhizal fungi from Volcano Usu on performance of Populus maximowiczii seedlings.

  obase keisuke, tamai yutaka, yajima takashi, miyamoto toshizumi

  The Japanese Forest Society Congress 日本森林学会 118 94 - 94 2007
• Regeneration and ectomycorrhiza formation of Larix kaempferi at Mt. Komagatake, Hokkaido.

  Usami Horoka, Tamai Yutaka, Yajima Takashi, Miyamoto Toshizumi

  The Japanese Forest Society Congress 日本森林学会 118 93 - 93 2007
• Changes in viability of the seeds of some tree species infected with Racodium therryanum

  Kondou Wataru, Miyamoto Toshizumi, Sano Yuzou, Tamai Yutaka, Yajima Takashi

  The Japanese Forest Society Congress 日本森林学会 118 638 - 638 2007
• Pileus differentiation and pileus-specific protein expression in Flammulina velutipes

  Yuichi Sakamoto, Akira Ando, Yutaka Tamai, Takashi Yajima

  FUNGAL GENETICS AND BIOLOGY 44 (1) 14 - 24 1087-1845 2007/01 [Refereed][Not invited]
   

  Fruiting bodies of Flammulina velutipes formed under complete darkness had a poorly developed pileus on top (pinhead fruiting body), and lacked a hymenium. Upon light stimulation, the pileus immediately began to develop on the apical region of the pinhead fruiting body. Swelling of the apical region caused by cell division was observed 2 days after light treatment; at day 4, the junction fracture between the pileus and stipe, and formation of the hymenium primordia were observed; at 6 days, gills were observed. We identified a cell wall-associated protein (PSH) that was specifically induced in the pileus, but not in the stipe, following light treatment of the pinhead fruiting body. Cloning and sequence analysis of the gene encoding PSH (psh) revealed a motif in the C-terminal region of the predicted amino acid sequence that was similar to hydrophobin. The level of transcription of psh was low in the stipe, but it was expressed at a high level in the pileus of the normal fruiting body. Transcription was also low in pinhead fruiting bodies, but increased after light treatment. These results indicate that psh is specifically expressed during pileus differentiation induced by light stimulation. (c) 2006 Elsevier Inc. All rights reserved.
• Arbuscular mycorrhizal fungi increased early growth of two nontimber forest product species Dyera polyphylla and Aquilaria filaria under greenhouse conditions

  Maman Turjaman, Yutaka Tamai, Erdy Santoso, Mitsuru Osaki, Keitaro Tawaraya

  MYCORRHIZA 16 (7) 459 - 464 0940-6360 2006/10 

  Nontimber forest products (NTFPs) represent an important source of income to millions of people in tropical forest regions, but some NTFP species have decreased in number and become endangered due to overexploitation. There is increasing concern that the planting stocks of Dyera polyphylla and Aquilaria filaria are not sufficient to sustain the yield of NTFPs and promote forest conservation. The objective of this study was to determine the effect of two arbuscular mycorrhizal (AM) fungi, Glomus clarum and Gigaspora decipiens, on the early growth of two NTFP species, D. polyphylla and A. filaria, under greenhouse conditions. The seedlings of both species were inoculated with G. clarum or G. decipiens, or uninoculated (control) under greenhouse conditions. Percentage of AM colonization, plant growth, survival rate, and nitrogen (N) and phosphorus (P) concentrations were measured after 180 days of growth. The percentage of AM colonization of D. polyphylla and A. filaria ranged from 87 to 93% and from 22 to 39%, respectively. Colonization by G. clarum and G. decipiens increased plant height, diameter, and shoot and root dry weights. Shoot N and P concentrations of the seedlings were increased by AM colonization by as much as 70-153% and 135-360%, respectively. Survival rates were higher in the AM-colonized seedlings at 180 days after transplantation than in the control seedlings. The results suggest that AM fungi can accelerate the establishment of the planting stocks of D. polyphylla and A. filaria, thereby promoting their conservation ecologically and sustaining the production of these NTFPs economically.
• Inocybe nitidiuscula, new to Japan

  Keisuke Obase, Takahito Kobayashi, Toshizumi Miyamoto, Yutaka Tamai, Takashi Yajima

  Mycoscience 47 (5) 293 - 297 1618-2545 2006 [Refereed][Not invited]
   

  A species of the genus Inocybe, which has not been recorded previously in Japan, is described and illustrated as a new record. Inocybe nitidiuscula (Britzelm.) Sacc. belongs to the subgenus Inocibium (Earle) Singer. © 2006 The Mycological Society of Japan and Springer-Verlag.
• Optimum temperature and pH for mycelial growth of Cordyceps nutans Pat. (Ascomycetes)

  Fumito Sasaki, Toshizumi Miyamoto, Yutaka Tamai, Takashi Yajima

  International Journal of Medicinal Mushrooms 7 (1-2) 301 - 304 1521-9437 2005 [Refereed][Not invited]
   

  Cordyceps nutans Pat. is an entomopathogenitic Ascomycete belonging to the family Clavicipitaceae and is parasitic on hemipteran insects. Very few investigations have been made with this fungus. C. nutans grows very slowly. Thus, further evaluation of culture conditions was necessary. In this research, we examined optimum temperature and pH for mycelial growth of C. nutans. In order to find the optimal culture temperature for growth, three strains were incubated at 5, 10, 15, 20, 25, 30, and 35 °C in darkness for 3 months, with six repetitions. Seven initial pH conditions of the media were adjusted by using 1 N HCl or KOH, and set at every 1.0 pH level from 5.0 to 11.0. Cultures were incubated at 25 °C for 3 months in replicates of six. Mycelial growth was observed at 10-25 °C and was greater at 20 and 25 °C. At 5, 30, and 35 °C, mycelial growth was not observed in any of the strains. Mycelial growth was observed at pH levels from 6.0 to 11.0 and not observed at pH 5.0. The overall tendency was that the strains grew relatively well in neutral to weak alkaline pH levels (pH 7.0-9.0) compared with acidic pH levels, but colonies were sparse. © 2005 by Begell House, Inc.
• Isolation of vegetable wasps and plant worms, Cordyceps nutans, from fruit-body tissue.

  Fumito Sasaki, Toshizumi Miyamoto, Yutaka Tamai, Takashi Yajima

  Journal of invertebrate pathology 85 (2) 70 - 3 0022-2011 2004/02 

  We isolated Cordyceps nutans from the stipe and abdominal tissues of fruit bodies using a surface sterilization method. Hyphal growth was observed in inocula from both the stipe and abdominal tissue. Some strains from discharged ascospores were obtained and colony characteristics were compared to the strains isolated from the tissues. Colonies of isolates from ascospores grew quite slowly. Isolates of 43 from the 52 examined fruit bodies formed colonies similar to those from ascospores. To confirm the success of isolation, we analyzed by PCR-RFLP of the ITS regions of rDNA samples from fruit bodies, isolates from fruit bodies, and isolates from ascospores. All the isolates obtained from stipe and abdominal tissues presented identical patterns. In this study, we report the first successful isolation of C. nutans from fruit-body tissue using a surface sterilization method.
• Influence of light on the morphological changes that take place during the development of the Flammulina velutipes fruit body

  Yuichi Sakamoto, Yutaka Tamai, Takashi Yajima

  Mycoscience 45 (5) 333 - 339 1340-3540 2004 [Refereed][Not invited]
   

  We show that fruit bodies of Flammulina velutipes can be induced in complete darkness after a sharp temperature reduction (23° to 16°C). However, the fruit bodies that form in complete darkness have a long stipe with an undeveloped pileus on the top (pinhead fruit bodies) and are thinner and whiter than the normal fruit bodies which are formed in the light. This finding suggests that F. velutipes fruit bodies cannot mature in complete darkness. However, when we irradiated the fruit bodies that had formed in complete darkness, a pileus developed immediately, and 4 days later the separation between the stipe and the pileus could be observed. Immediately after light exposure, the stipe also thickened and became increasingly pigmented. The stipe elongation was inhibited until 8 days after light exposure, although stipe elongation progressed very quickly thereafter. Basidospores were also visible in the gills 8 days after light exposure. We consider that the basidiospore development is involved in this rapid stipe elongation, which aids the effective dispersal of basidiospores.
• Protein expressions during fruit body induction of Flammulina velutipes under reduced temperature

  Y Sakamoto, A Ando, Y Tamai, K Miura, T Yajima

  MYCOLOGICAL RESEARCH 106 222 - 227 0953-7562 2002/02 [Refereed][Not invited]
   

  The influences of temperature on the fruit body induction of Flammulina velutipes were investigated. The fruit body could be induced after reducing of the ambient temperature under complete darkness, but could not be induced after light irradiation without temperature reduction. Fruit bodies formed under complete darkness elongated without pileus formation (pinhead fruit body). Protein expression patterns were investigated by two-dimensional electrophoresis, and 22 protein spots were found to be newly expressed in the mycelia and fruit bodies after reducing of the ambient temperature, but few protein spots were newly expressed in the mycelia after light irradiation without temperature reduction. Four of the spots had identical N-terminal sequences to polypeptides, Pf1, Pf3, Pfd3, and Pf6 which are previously sequenced as polypeptides expressed specifically during fruit body formation of F. velutipes.
• A gene encoding a hydrophobin, fvh1, is specifically expressed after the induction of fruiting in the edible mushroom Flammulina velutipes

  A Ando, A Harada, K Miura, Y Tamai

  CURRENT GENETICS 39 (3) 190 - 197 0172-8083 2001/05 [Refereed][Not invited]
   

  A cDNA clone of the gene fvh1 was previously isolated from a preprimordial cDNA library made from the basidiomycete Flammulina velutipes. Sequence analysis showed that fvh1 encoded for a hydrophobin, a small fungal protein usually secreted by filamentous fungi. FVH1 had a highly conserved arrangement of eight cysteine residues, a putative N-terminal signal sequence and a hydropathy pattern characteristic of class I hydrophobin. A genomic fvh1 clone was isolated from a F. velutipes genomic DNA library and sequenced. Several putative promoter elements and three small introns of fvh1 were identified in this clone. Southern blot analysis of genomic DNA showed that fvh1 was a single copy gene. Northern analysis indicated that fvh1 was specifically and abundantly expressed in mycelia after the induction of fruiting and during fruit body initiation. It was not expressed in mycelia before the induction of fruiting or in mature fruit bodies.
• Isolation and characterization of a novel anionic peroxidase cDNa found in poplar (Populus nigra) suspension cultured cells

  Yoshiaki Kato, Yoh Sakuma, Tomonori Azuma, Akira Ando, Kiyoshi Miura, Keiji Takabe, Yutaka Tamai

  Journal of Wood Science 47 (3) 165 - 170 1435-0211 2001 [Refereed][Not invited]
   

  A cDNA clone from Populus nigra L. var. italica Koehne, denoted PCY2-6, coding for an anionic peroxidase has been isolated, cloned, and characterized. PCY2-6 is 1160 bp long and its deduced product, PnC26, contains 343 amino acid residues. The mature protein has a calculated isoelectric point of 4.09. The protein contains two motifs typical of peroxidase and 10 potential W-glycosylation sites. PnC26 is therefore classified as an anionic peroxidase. The mRNA of the PCY2-6 gene family was detected in immature and mature leaves and in two parts of current-year stems: the shoot tip and the older stem. The mRNA of PCY2-6 gene family was found to localize in the phloem and cortex of the current-year stems. We therefore conclude that expression of the PCY2-6 gene family is related to bark development.
• ELECTROFUSION OF THE AUXOTROPHIC MUTANTS OF RHIZOCTONIA-SOLANI

  T YOKONO, Y TAMAI, K MIURA, T KAYAMA, M HYAKUMACHI

  MOKUZAI GAKKAISHI 34 (2) 176 - 180 0021-4795 1988 [Not refereed][Not invited]
  

MISC

• カラマツコンテナ苗の成長に及ぼす水分環境の影響

  西井あす香, 菅井徹人, 玉井裕, 斎藤秀之, 澁谷正人, 小池孝良  北方森林研究  (66)  27‐30  2018/02/28  [Not refereed][Not invited]
  
• Biodiversity of ectomycorrhiza of 3 larch species grown under different phosphorous and nitrogen levels in weathered volcanic ash soil

  WANG Xiaona, MAO Qiaozhi, QU Laiye, TAMAI Yutaka, WATANABE Makoto, Koyama Akihiro, KOIKE Takayoshi  Boreal forest research  (61)  45  -47  2013/02/18
• Vegetation and Colonization Status of Mycorrhizal and Endophytic Fungi in Plant Species on Acidic Barren at Crater Basin of Volcano Esan in Hokkaido, Japan

  Fukuchi Souta, Obase Keisuke, Tamai Yutaka, Yajima Takashi, Miyamoto Toshizumi  Eurasian Journal of Forest Research  14-  (1)  1  -11  2011/08  

  We investigated the colonization status of mycorrhizal and endophytic fungi in roots of plants established on an acidic barren at volcano Esan, Hokkaido, Japan. In total, 87 individuals of 21 plant taxa were investigated in four different vegetation sites and the surrounding area. Ericaceous plants such as Empetrum nigrum var. japonicum, Ledum palustre var. diversipilosum, Vaccinium vitis-idaea var. minus and Loiseleuria procumbens were the main colonizers at the study sites and dominated under even the most severe conditions of low soil moisture and nutrient content. They were associated with ericoid mycorrhizal (ERM) fungi at all vegetation sites and erratically with dark septate endophytic (DSE) fungi. They commonly associated together with arbuscular mycorrhizal (AM) fungi only at sites where Sasa senanensis dominated. Among the ericaceous plants, only Enkianthus campanulatus associated with AM and DSE fungi and had no associations with ERM fungi. Other herbaceous and woody plants associated commonly with AM or erratically with DSE fungi, except for Carex sp. and Polygonum spp. which erratically associated with AM and DSE fungi. Mycorrhizal associations were common in representative vegetation on the crater basin of Mt. Esan. In particular, ERM associations might play a significant role in invasion and establishment of ericaceous plants, and also in the development of plant communities in the harsh environment at Mt. Esan.
• Shortening Effect of Charcoal on the Cultivation Period of Bunashimeji Mushroom (Hypsizygus marmoreus)

  SUGIYAMA Ryoji, TAMAI Yutaka, YAJIMA Takashi, MIYAMOTO Toshizumi, HARADA Akira  Journal of the Japan Wood Researh Society  57-  (4)  223  -226  2011/07/25
• 蛇紋岩土壌に植栽したグイマツ雑種F1の成長と外生菌根形成に対する窒素付加の影響

  笠小春, 渡辺誠, 玉井裕, 小池孝良, 柴田英昭, 高木健太郎, 野村睦  日本森林学会大会学術講演集(CD−ROM)  120th-  ROMBUNNO.PA3-06  2009/03/25  [Not refereed][Not invited]
  
• Combinational effects of various distributions of charcoal and ectomycorrhiza in soil on the growth of Larix gmelinii. seedlings

  KOBAYASHI Makoto, KIM Yong-Suk, KOJIMA Yasuo, TAMAI Yutaka, KOIKE Takayoshi  Transactions of the Meeting in Hokkaido Branch of the Japanese Forest Society  (57)  57  -59  2009/02/21
• Morphological and molecular characterization of Pisolithus occurring in Hokkaido Island, Northern Japan

  KASUYA Maria Catarina Megumi, COELHO Irene da Silva, TAMAI Yutaka, MIYAMOTO Toshizumi, YAJIMA Takashi  Mycoscience  49-  (5)  334  -338  2008/10/25
• 有珠山噴火跡地におけるヤナギ類稚樹の外生菌根菌相

  小長谷啓介, 玉井裕, 矢島崇, 宮本敏澄  日本森林学会大会学術講演集(CD-ROM)  117th-  (0)  F29  -162  2006/04/03  [Not refereed][Not invited]
  
• 有珠山噴出物堆積地で確認された外生菌根菌

  小長谷啓介, 玉井裕, 矢島崇, 宮本敏澄, YOGANATH Adikari  日本森林学会大会講演要旨集(CD-ROM)  116th-  (0)  2B21  -216  2005/03/20  [Not refereed][Not invited]
  
• 噴火3年後の有珠山で確認された実生と菌根の形成状態

  小長谷啓介, YOGANATH A, 宮本敏澄, 玉井裕, 矢島崇  日本林学会大会学術講演集  115th-  653  2004/03/20  [Not refereed][Not invited]
  
• Differential protein expression in the fruiting dikaryon and the non-fruiting monokaryon of Flammulina velutipes

  Y Sakamoto, A Ando, Y Tamai, K Miura, T Yajima  MYCOLOGICAL RESEARCH  105-  (2)  177  -182  2001/02  [Not refereed][Not invited]
   

  Patterns of protein expression in the monokaryons and the derived dikaryon of the basidiomycete Flammulina velutipes were investigated using two-dimensional polyacrylamide gel electrophoresis and silver staining. Over 300 spots were detected on each gel, and 19 proteins were expressed in the dikaryon before fruiting treatment but not expressed in the monokaryon before fruiting treatment. On the of her hand, 9 proteins were expressed in the monokaryon specifically. Newly expressed proteins increased after fruiting treatment (at 7 d and 14 d), but decreased after fruit bodies were formed (at 21 d). The number of newly expressed proteins after the fruiting treatment was similar in the monokaryon. Proteins expressed characteristically were classified into 7 types. The highest number of proteins (13 proteins) were specifically expressed in the dikaryon at 14 d when the fruit-bodies were formed. Twenty-seven proteins were expressed specifically in the fruit body. Fruit body specific proteins Pf1 and Pf3 were sequenced. This revealed Pf1 and Pf3 had amino acid sequences that were similar to each other, as well as a high similarity to the deduced amino acid sequence of the FDS gene isolated from F. velutipes.
• Characterization of proteins expressed abundantly in the fruit-body of Flammulina velutipes

  Yuichi Sakamoto, Tomonori Azuma, Akira Ando, Yutaka Tamai, Kiyoshi Miura  Mycoscience  41-  (3)  279  -282  2000/06/15  [Not refereed][Not invited]
   

  Chronological changes of protein expression in the vegetative mycelium of Flammulina velutipes and expression of these proteins in the fruit-body were investigated by two-dimensional polyacrylamide gel electrophoresis. Four proteins (FBA1-4) expressed abundantly in the fruit-body were found to have different expression patterns in the vegetative mycelium after the fruiting treatment. FBA1-4 had similar amino acid sequences and displayed a high similarity with the deduced amino acid sequence of the C1 cDNA, which has an Arg-Gly-Asp (RGD) cell-attachment sequence. This suggests that FBA 1-4 may have cell-to-cell attachment activity.
• Characterization of proteins expressed abundantly in the fruit-body of Flammulina velutipes

  Yuichi Sakamoto, Tomonori Azuma, Akira Ando, Yutaka Tamai, Kiyoshi Miura  Mycoscience  41-  (3)  279  -282  2000/06/15  [Not refereed][Not invited]
   

  Chronological changes of protein expression in the vegetative mycelium of Flammulina velutipes and expression of these proteins in the fruit-body were investigated by two-dimensional polyacrylamide gel electrophoresis. Four proteins (FBA1-4) expressed abundantly in the fruit-body were found to have different expression patterns in the vegetative mycelium after the fruiting treatment. FBA1-4 had similar amino acid sequences and displayed a high similarity with the deduced amino acid sequence of the C1 cDNA, which has an Arg-Gly-Asp (RGD) cell-attachment sequence. This suggests that FBA 1-4 may have cell-to-cell attachment activity.
• Rapid prediction of native wood pulp properties by Fourier transform Raman spectroscopy

  T Ona, T Sonoda, K Ito, M Shibata, T Kato, Y Ootake, Y Tamai, Y Kojima  JOURNAL OF PULP AND PAPER SCIENCE  26-  (2)  43  -47  2000/02  [Not refereed][Not invited]
   

  The feasibility of using Fourier transform Raman spectroscopy for rapid assessment of various pulp properties was examined using two Eucalyptus species, including samples of various ages and colours, which are of importance as a plantation source. Pulp properties, namely pulp yield, sheet density, burst factor; breaking length, tear factor; unbleached brightness and Kappa number were measured. The application of 2nd derivatives transformation of Raman spectroscopic data revealed highly significant correlations between measured and Raman predicted values for all traits with correlation coefficient (r) > 0.998 in the calibration (for known samples) and r > 0.882 in the prediction (for unknown samples), respectively. Consequently, this rapid method has suggested its validity for analyzing Eucalyptus native wood meal samples, regardless of their age and colour to assess pulp properties.
• 葉中のフェノール成分によるカバノキ属樹木のケモタキソノミー

  北海道大学農学部付属演習林研究報告  57-  (1)  53  -65  2000  [Refereed][Not invited]
  
• Effect of moisture content of a wood matrix on a small-scale biodegradation system for organic solid waste

  S Horisawa, Y Tamai, Y Sakuma, S Doi, M Terazawa  JOURNAL OF WOOD SCIENCE  46-  (4)  317  -321  2000  [Not refereed][Not invited]
   

  The optimum working moisture content of a wood matrix for the garbage automatic decomposer-extinguisher (GADE) machine was investigated using a small-scale degradation reactor. A formula feed for rabbits was used as the model waste. The degradation experiment was conducted under controlled conditions such as moisture content, environmental temperature, and airflow rate. The degradation rate was estimated precisely from weight loss and the CO2 evolution rate. The degradation rate were nearly constant at a moisture content of 30%-80% on a wet-weight basis. Microorganisms from the environment propagated in the reactor with no inoculums added. The number of microorganisms showed a trend similar to that of the degradation rate. The microorganism community changed according to the moisture content of the matrix and were considered to attain a constant degradation rate at a wide range of moisture content of a matrix.
• Biodegradation of non-lignocellulosic substances (]G0003[) : Effects of hot-and cold-water extractives of sawdust on bacterial multiplication(共著)

  Research Bulletin of the Hokkaido University Forests  57-  (1)  66  -70  2000  [Not refereed][Not invited]
  
• Screening of heterozygous DNA markers in shiitake (Lentinula edodes) using de-dikaryotization via preparation of protoplasts and isolation of four meiotic monokaryons from one basidium

  K Miyazaki, H Maeda, M Sunagawa, Y Tamai, S Shiraishi  JOURNAL OF WOOD SCIENCE  46-  (5)  395  -400  2000  [Not refereed][Not invited]
   

  A suitable screening method for heterozygous DNA markers in shiitake, Lentinula edodes (Berk.) Pegler, is reported. Monokaryons were derived from a dikaryon by de-dikaryotization via protoplast formation. Compatibility of the monokaryons was determined by pairwise culture on agar plates. We selected the primers to amplify polymorphic fragments among the original strain (Hokken600:H600) and two monokaryons (H600PP-39 and H600PP-67) showing compatibility. A total of 135 fragments were selected as specific random amplified polymorphic DNAs (RAPDs) resulting from 56 primers of the 147 primers tested. Furthermore, we tested whether the polymorphic fragments segregated into 2:2 among four strains isolated from a basidium. Most of the polymorphic fragments (about 97.8%) showed 2:2 segregation among the four strains. We concluded that the polymorphic fragments were heterozygous if they were detected in either of the monokaryons (H600PP-39 and H600PP-67) and segregated to 2:2 among four meiotic strains (H600B-1, 2, -3, and -4). A total of 132 heterozygous DNA markers were therefore selected from a dikaryon of shiitake (Hokken600: H600).
• Analysis of the electrophoretic karyotype of Flammulina velutipes

  D Kim, Y Tamai, T Azuma, A Harada, A Ando, Y Sakuma, K Miura  JOURNAL OF WOOD SCIENCE  46-  (6)  466  -469  2000  [Not refereed][Not invited]
   

  The karyotype of Flammulina velutipes (Curt.: Fr.) Sing. was analyzed electrophoretically using contour-clamped homogeneous electric field gel electrophoresis and hybridization with DNA probes. The chromosomal DNA from the monokaryon (Fv-4K) and the dikaryon (Fv-4) were resolved into six and eight bands, respectively. The sizes of the chromosomes ranged from 1.9 to 6.0 megabase (Mb) pairs. Each of the separated bands of chromosomal DNA. was identified by use of five cloned probes. The number of these chromosomes was estimated to be 6 and 12, respectively; and the size of the entire genome was estimated to be about 20.1 and 38.6Mb, respectively. From a comparison of the hybridization patterns, the existence of allelic chromosomes of different sizes was deduced in the Fv-4 strain.
• Karyotype analysis of interspecific fusants of basidiomycetes by pulsed-field gel electrophoresis

  T Yokono, Y Tamai, T Azuma, Y Sakuma, K Miura, Y Kojima, M Sunagawa, M Ohmasa  JOURNAL OF WOOD SCIENCE  46-  (6)  480  -484  2000  [Not refereed][Not invited]
   

  The purpose of this research was to analyze the karyotype of the interspecific fusants of two Pleurotus species. Auxotrophic mutants derived from the cultivated strain of P. ostreatus and P. cornucopiae were used. Protoplasts were fused electrically, and the fusants were selected under auxotrophic complementation. Esterase isozyme analysis showed that several fusants had isozyme bands originating from both parental strains, and others had unilateral isozyme bands. The fusant that had expressed isozyme bands of both parental strains showed chromosomal DNA bands of both of the parental strains in pulsed-field gel electrophoresis analysis. Despite the above results, the chromosomal composition of the fusants obtained by the pulsed-field gel electrophoresis did not exhibit all of the bands of both fusion parents.
• Chemical Constituents of ┣DB Inonotus obliquus (/)-┫DB (]G0001[)(共著)

  Eurasian Journal of Forest Research  1-  43  -50  2000  [Not refereed][Not invited]
  
• Investigation of change in tangential strain on the inner bark of the stem and root of Betula platyphylla var. japonica and Acer mono during sap season

  YOSHIDA Masato, YAMAMOTO Osamu, TAMAI Yutaka, SANO Yuzou, TERAZAWA Minoru, OKUYAMA Takashi  Journal of Wood Science  45-  (5)  361  -367  1999/10/25
• ナラタク属菌によるシイタクほだ木の侵害(共著)

  日本応用きのこ学会誌  7-  (2)  71  -74  1999  [Not refereed][Not invited]
  
• Biodegradation of nonlignocellulosic substances II: physical and chemical properties of sawdust before and after use as artificial soil

  S Horisawa, M Sunagawa, Y Tamai, Y Matsuoka, T Miura, M Terazawa  JOURNAL OF WOOD SCIENCE  45-  (6)  492  -497  1999  [Not refereed][Not invited]
   

  The physical properties of sawdust including porosity, water retention, and water drainage were analyzed to prove its suitability for use as an artificial soil in the automatic decomposer-extinguisher (GADE) machine. The physical and chemical properties of residual sawdust from the GADE machine were also analyzed, the mechanical abrasion of sawdust in the GADE machine was tested, and the morphology of this residue was observed through a scanning electron microscope to investigate changes of these properties in the medium of decomposing garbage. Sawdust, which showed a lower specific gravity and larger porosity than soil, is considered capable of supplying air to bacteria. Tt was found that sawdust became worn from the operation of the machine. The spaces of residual sawdust were still observed, but water drainage decreased. The portion of hollocellulose in residual sawdust decreased, although the extractives in it increased, Results indicated that the capacity of sawdust to function as an artificial soil in the GADE machine was decreased owing not only to the destruction of sawdust grain but also to the adherence of products from decomposition, such that sawdust needed to be replaced every few months.
• Biodegradation of nonlignocellulosic substances I: system for complete decomposition of garbage using sawdust and aerobic soil bacteria

  M Terazawa, S Horisawa, Y Tamai, K Yamashita  JOURNAL OF WOOD SCIENCE  45-  (4)  354  -358  1999  [Not refereed][Not invited]
   

  A system for effective garbage decomposition using sawdust and aerobic soil bacteria was examined. The machinery used in this process, the garbage automatic decomposer-extinguisher (GADE), is composed of a container with an automatic mechanical mixer and a drain for liquid formed by the decomposition of garbage. The aerobic soil bacteria, cultivated in sawdust, degrades garbage within the container. The GADE machine, containing 4 kg of sawdust, totally decomposed 59.75 kg of garbage within 3 months (0.66 kg/day). Constant temperature, pH level, and moisture content of the matrix throughout the experimental period suggested stable degrading action. The residual sawdust and drainage water from the GADE machine were converted to fertilizers or soil conditioners (GADE compost) by the garbage decomposition process. Neither inhibited germination or growth of three test crops: komatsuna, Chinese cabbage (Brassica campestris), hatsukadaikon, radish (Raphanus sativus L. var, radicula), and bisai (Raphanus sp.).
• Cloning and Sequence Analysis cDNA for the Gene FVFD 30,Speci tically Expressed During Fruiting Body Development in ┣DBElammulina(/)-┫DB ┣DBvelutipes(/)-┫DB(共著)

  Mushroom Technology and Biotechnology  7-  (3)  95  -99  1999  [Not refereed][Not invited]
  
• Histological Characteristics and Decay Ability to Wood of Betula platyphylla SUKATCHEV var. japonica (MIQ.) HARA and Abies sachalinensis (FR. SCHM.) MAST. of 5 Hokkaido Armillaria in Japan

  Cha Joo Young, Tamai Yutaka, Miyamoto Toshizumi, Igarashi Tsuneo  Research bulletins of the College Experiment Forests, Hokkaido University  53-  (2)  235  -244  1996/09
• Analyses of fusants in edible mushrooms

  SUNAGAWA Masahide, TAMAI Yutaka, NEDA Hitoshi, MIYAZAKI Kazuhiro, MIURA Kiyoshi  Journal of the Japan Wood Researh Society  41-  (10)  945  -948  1995/10/25
• Development of Flammulina velutipes (Curt.: F_R.) SING, on street trees

  CHA Joo Young, MIYAMOTO Toshizumi, TAMAI Yutaka, IGARASHI Tsuneo  Transactions of the Meeting in Hokkaido Branch of the Japanese Forestry Society  (43)  42  -44  1995/02/28
• APPLICATION OF RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) MARKERS .1. ANALYSES OF FUSANTS IN EDIBLE MUSHROOMS

  M SUNAGAWA, Y TAMAI, H NEDA, K MIYAZAKI, K MIURA  MOKUZAI GAKKAISHI  41-  (10)  945  -948  1995  [Not refereed][Not invited]
   

  We analyzed several fusants between edible mushrooms (Auricularia auricula (Hook.) Underw. and A. polytricha (Mont.) Sacc., and between Pleurotus ostreatus (Jacq.: Fr.) Kummer and P. cornucopiae (Paulet) Rolland) by Random Amplified Polymorphic DNA (RAPD) markers. Four fusants (Fu 9, 52, 63, and 100) obtained by electrical protoplast fusion between A. auricula and A. polytricha showed three types of RAPD patterns. Especially, one fusant (Fu 100) possessed each of the specific bands of amplified DNA obtained from parental strains, A. auricula and A. polytricha. One fusant (OCD-15), between P. ostreatus and P.cornucopiae, obtained by electrical protoplast fusion, also possessed specific bands of both parental strains using RAPD analysis. It is suggested that RAPD markers are useful tools for the analyses of fusants in edible mushrooms.
• SEPARATION OF LARGE DNA-MOLECULES FROM PLEUROTUS-CORNUCOPIAE BY PULSED-FIELD GEL-ELECTROPHORESIS

  Y TAMAI, T YOKONO, M SUNAGAWA, Y KOJIMA, K MIURA  MOKUZAI GAKKAISHI  41-  (10)  952  -955  1995  [Not refereed][Not invited]
   

  An optimum condition for the separation of large DNA molecules from Pleurotus cornucopiae (Paulet) Rolland var. citrinopileatus (Sing.) Ohira was investigated by using the pulsed-field gel electrophoresis (PFGE) method. A clear separation of the DNA molecules was achieved by, a combination of switching intervals and running voltages. Nine and seven bands were separated from the dikaryon and the monokaryon, respectively, within 96 h. They ranged in size from 1.7 to 3.7 Mb. Their genome sizes were estimated as about 55.2 Mb and 27.8 Mb, respectively.
• CHARACTERIZATIONS OF THE STRAINS OF BASIDIOMYCETES WITH BAVENDAMM REACTION

  Y TAMAI, K MIURA  MOKUZAI GAKKAISHI  37-  (7)  656  -660  1991  [Not refereed][Not invited]
   

  Eighteen strains belonging to nine species of basidiomycetes were examined for Bavendamm's reaction to utilize their characteristics for the selection of fusants. Common coloration was observed only for tannic acid. Lentinus edodes (Berk.) Sing. showed coloration for alpha-naphthol, and the growth of hyphae was repressed strongly on eugenol. On the other hand, Pholiota nameko (T. Ito) S. Ito & Imai exhibited no coloration for alpha-naphthol, and was not repressed on eugenol. Such a complementary combination of characteristics were observed in some strains of different species. The results showed that these characteristics may be used as a marker for the selection of fusants.
• ELECTRICAL FUSION OF PROTOPLASTS BETWEEN 2 PLEUROTUS SPECIES

  Y TAMAI, K MIURA, T KAYAMA  MOKUZAI GAKKAISHI  36-  (6)  487  -490  1990  [Not refereed][Not invited]
  

Association Memberships

• 日本木材学会   日本菌学会   日本きのこ学会   リグニン学会   木質炭化学会   日本森林学会   

Works

• Research Bulletin of the Hokkaido University Forests,57(1)66-70(2000) Biodegradation of non-ligrocellulosic substances (]G0003[) : Effects of hot- and cold- water extractives of sawdust on bacterial multiplication(共著)

  2000

Research Projects

• Clarification of propagation reaction for lignin formation by using artificial polysaccharide matrix

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2021/04 -2026/03 

  Author : 浦木 康光, 堤 祐司, 玉井 裕, 綿岡 勲, 鈴木 栞, 重冨 顕吾

   

  当該年度は、3つの課題について検討を行い、以下の成果を得た。 1. rCWPO-Cの高純度化と多量発現：組換体大腸菌によるタンパク質の発現と精製工程にいて、TAPS化とリフォールディングの間に遠心分離を2回の行う操作を加えた。この結果、精製rCWPO-Cの収率を維持したまま、ペルオキシダーゼの精製度を示すRZ値が約1.5倍に増加し、比活性も約1.5倍の560μmol/min/mgまで向上した。 2.細胞壁構成多糖類間および多糖類-ペルオキシダーゼ間のの相互作用解析：木材のヘミセルロース（キシラン、グルコマンナン、キシログルカン）とセルロースとの相互作用を、平衡吸着実験と速度論的解析が可能なQCM-Dを用いて行った。両測定とも、キシログルカンがセルロースに最も吸着することが明らかとなった。また、Horseradish peroxidase(HRP)と多糖類との相互作用解析では、HRPはセルロースに対し、高い親和性を示すことも分かった。さらに、多糖類が脱水素重合体(DHP)の形成に及ぼす影響も調べ、キシログルカンがDHPを多量生成させ、加えて、5-5’縮合結合の形成も促進することが示された。この結果より、一次細胞壁が縮合構造に富む理由が解明できた。 3.高分子リグニンの蛍光共鳴エネルギー移動（FRET)の測定：FRET測定の最初の取り組みとして、固体試料を対象とした蛍光顕微鏡でFRETが示されているリグニンと蛍光試薬ローダミンとの相互作用を、溶液中で検出することから検討した。使用したリグニンは広葉樹のクラフトリグニンである。この測定の結果、プロピレングリコールを溶媒とする溶液中で、FRETを観測することができた。モノリグノールとクラフトリグニンとのFRETの検出を試みたが、どちらも蛍光強度が弱かったために、明確なFRET検出には至っていない。
• A study on mechanisms of barrier function in various types of outer bark of trees

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2020/04 -2023/03 

  Author : 佐野 雄三, 玉井 裕, 重冨 顕吾

   

  樹皮組織の抗菌活性評価実験系の前処理（滅菌）条件の検証を行うとともに、同実験系により対象樹種を拡げて樹皮組織に対する菌類の抗菌活性評価を行った。また、前年度の研究で顕著な抗菌活性が認められたナナカマドについて、化学的なメカニズムの検討と内生菌相の解析を行った。主な成果は以下の通りである。 【抗菌活性評価実験系の前処理（滅菌）条件の検討】前年度にサンプルの前処理として15 kGyのγ線照射が有効であることを確認したが、フレッシュな樹皮組織で必要且つ十分な線量については未検討であった。そこで、16樹種のサンプルについて3 kGy刻みで検証し、15 kGyの照射線量は妥当なレベルであることを確証した。【樹皮片に対する菌類の忌避性・成長阻害活性評価】上述の評価実験系により、新たに10樹種について試験を行った。前年度に見出されたナナカマドのような強い活性を示すものは認められなかったが、新たに2樹種（エゾマツ、オオヤマザクラ）が明らかな成長阻害活性を示した。このうちエゾマツでは、樹皮組織片とカワラタケの分断実験の結果から、その原因物質は揮発性ではないことが示唆された。【ナナカマド樹皮の抗菌活性発揮メカニズム】アミグダリンに着目し、解析を行なった。樹皮組織にも含まれること、アミグダリン（標品）がβ-グルコシダーゼとの共存下でシアン化水素を発生し、ナナカマドの樹皮組織片と同様にカワラタケの成長を阻害すること、ナナカマドから採取した樹皮組織が実際にシアン化水素を発することが確認され、アミグダリンがバリア機能発揮に大きく寄与していることが示唆された。【ナナカマド樹皮組織の菌叢】内生菌がバリア機能強化に寄与する可能性を検討するため、菌叢解析を行なった。内樹皮では菌が検出されず、外来の共生菌類のバリア機能発揮への寄与は小さいことが示唆された。
• Mechanisms to avoid occurrence of Ash dieback on the introduced ash species surviving in Japan

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2019/04 -2022/03 

  Author : Yamaoka Yuichi

   

  To clarify why some introduced ash species planted in Hokkaido, including on the campus of Hokkaido University, grow well without suffering serious diseases such as Ash dieback, monitoring of the behavior of Hymenoscyphus fraxineus in the leaves of ash trees, comparison of resistance by inoculation experiments using seedlings, detection and isolation of phyllosphere fungi from the leaves of the ash trees, and screening of phyllosphere fungi against H. fraxineus were conducted. As a result, European ash (F. excelsior) trees planted on the campus of Hokkaido University were infected with H. fraxineus similar to other ash species, but they showed the ability to inhibit growth of H. fraxineus in the infected cells and tissues. Some phyllosphere fungi, Diaporthe pseudomangiferae and Aureobasidium pullulans were antagonistic to H. fraxineus, indicating they may contribute to the inhibition of H. fraxineus in European ash.
• Investigation of lignin formed in the mimetics of wood cell wall and clarification of lignification-related compounds

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2018/04 -2021/03 

  Author : Uraki Yasumitsu

   

  This study clearly demonstrated the effect of hemicelluloses on ligninfication through lignin formation in the artificial polysaccharide matrices; xylan contributed to lignin formation and generation of 8-O-4' interunitary linkage, which was a major linkage in native lignin, while glucomannan inhibited lignin formation. In addition, xyloglucan, which located only at primary wall of tree, was found to enhance the frequency of 5-5' interunitary linkage. From the analysis of solution structure for isolated lignins by using size-exclusion chromatograph equipped with multi-angle laser light scattering detector, 5-5' linkage was found to be closely related to the densed structure, especially much compact structure of lignin fraction with larger molar mass compared to that with small molar mass.
• Ecology and diversity of Hymenoscyphus fraxineus, the causal agent of ash dieback in Europe in the areas near origin, and risk assessment as invasive plant pathogen

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2015/04 -2018/03 

  Author : YAMAOKA Yuichi, MASUYA Hayato, ABE Junichi, TAMAI Yutaka, YAMAGUCHI Takehiro

   

  Hymenoscyphus fraxineus causeing a lethal disease known as ‘ash dieback’ of Fraxinus excelsior in Europe is considered to be originated from East Asia. In Japan, this fungus produces apothecia on decomposing leaves of manshurian ash, F. mandshurica from middle July to early September. Results of detection of the fungus from periodically collected leaves of F. mandshurica by real-time PCR assays using species specific primers revealed that after infected the living leaves of by ascospores, H. fraxineus endophytically inhabited in them until defoliation. This fungus was also able to infect other Fraxinus species, including F. excelsior, F. pennsylvanica, and F. augustifolia, but no serious damages like ash dieback were observed in these ashes except for one population of F. pennsylvanica in Hokkaido. Some resistant reactions controlling movement of the fungus into stem tissues and/or environmental factor like overwinter condition might affect on symptom development.
• Lignification in polysaccharide matrix mimicking wood cell wall and clarification of lignin structure -control factor

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2014/06 -2018/03 

  Author : Uraki Yasumitsu

   

  An aim of this study is to elucidate lignin formation mechanism (lignification), especially influence of hemicelloses, with polysaccharide matrix mimicking wood cell wall structure. Polysaccharide matrix was successfully prepared by the deposition of hemicelluloses, xylan and glucomannan, onto bacterial cellulose. Dehydrogenative polymerization of coniferyl alcohol, which was one of monolignols, was attempted in the presence of such polysaccharide matrix. As a result, the polymerization was accelerated by xylan deposition, but was inhibited by glucomannan. In addition, the structure of the resultant polymerized product (Dehydronation Polymer: DHP) was investigated on a size-exclusion chromatography equipped with a laser light-scattering detector by the comparison with solution structure of a non-branched lignin model compound that is comprised of only 8-O-4’ linkage. This investigation revealed that DHP had a significant frequency of branched structure.
• Combination Effect of elevated O3 and CO2 on growth of larch species and species diversity of ectomycorrhizae

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2014/04 -2016/03 

  Author : KOIKE Takayoshi, TAMAI Yutaka, WATANABE Makoto

   

  We studied colonization of ectomycorrhiza (ECM) fungi and the species abundance of a hybrid larch F1 (Larix gmelinii var. japonica × L. kaempferi) with elevated CO2 and ozone (O3). Two-year-old seedlings were planted in an Open-Top-Chamber (OTC) system with 4 gas fumigations: Control (< 6 nmol/mol), O3 (60 nmol/mol), CO2 (600 μmol/mol), and CO2+O3. After 2 growing seasons, ECM colonization and root biomass were positively affected by elevated CO2. Ozone impaired ECM colonization rate and species richness, and reduced stem biomass. However there was no clear inhibition on photosynthetic capacity by O3. Concentration of most elements (Al, Fe, Mo, P) in needles was reduced by O3 but some increased in roots (K, Mg), which may lead to distinct alteration of ECM abundance. We found no effects of combined fumigation on all parameters except P concentration in needles. Tolerance to O3 shown in hybrid larch F1 might be potentially related to ECM symbiosis changes.
• Clarification of hemicellulose functions using artificial wood cell wall and development of its functional materials

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2009 -2011 

  Author : URAKI Yasumitsu, TAMAI Yutaka, KODA Keiichi, HIRAI Takuro, SUGIYAMA Junji

   

  In this study, hemicellulose-adsorbed honeycomb-patterned cellulose films termed as artificail wood cell wall were developed to investigate the function of hemicelluloses in wood cell wall and to develop the cell culture for liver cells. Tensile strength and its modulus of the cellulosic films were enhanced by the adsorption of hemicelluloses, xylan and arabinogalactan (AG). Xylan adsorption and its tensile modulus were improved by microwave irradiation. We judged proposed theory for the elucidation of deformation mechanism of wood cross-scetion upon the mechanical stress from the tensile properties of honeycomb-patterned films. As a result, the theory of bending-stretching model was suitable for the elucidation, and xylan-adsorbed film showed more fitting to the theory. In addition, we evaluated AG-adsorbed honeycomb-patterned film as a culture substrate for mouse liver cells. The films with small pores were found to be a new type candidate substrate for the culture. On the other hand, the films with larger pores would be suggested to be a plate for cell array, but the number of attached cell was so small. For the industrial application, this problem should be overcome.
• Complete understanding of the nitrogen missing link in boreal forest ecosystems and evaluation of nitrogen provision and loss

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2008 -2011 

  Author : HASHIDOKO Yasuyuki, HARAGUCHI Akira, KOIKE Takayoshi, HATANO Ryusuke, TAMAI Yutaka, HORIUCHI Junichi, MIYAMOTO Toshizumi

   

  Nitrogen imbalance of the boreal forest ecosystem has long been a mystery, called missing link of nitrogen in boreal forest. We challenged to this mystery, to practically understand the effects of climate change on forest biomass productivity in several types of boreal forests. Precise investigation of optimal culture conditions including compositions of the medium were obviously close to the reported conditions of the forest bed soil in summer seasons. The 16S rRNA gene-targeting DGGE analysis combined with gellan gum medium revealed the presence of Dugnella (class y-Proteobacteria) and Clostridiumin (phylum Firmicutes) in the A-horizon of the subarctic tundra soil, and also showed the aboveground vegetation affect on bacterial activity in soil. Thus, it was strongly suggested that scale of the elemental circulation in the boreal forests near the forest limit highly regulates acetylene reducing activity of free-living nitrogen-fixing bacteria. Also it was speculated that the low acetylene reduction in the forest bed soil would be highly regulated as corroborative events together with ericoid mycorrhizal and/or ectomycorrhizal fungi, leading to effective nitrogen supply to the forest ecosystem.
• Investigation for functionalities of rhizo-biocomplex to minimize highly adverse conditions in association with organic sink in the rhizosphere and its utilization in agricultural use

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2008 -2011 

  Author : HASHIDOKO Yasuyuki, HARAGUCHI Akira, KIMURA Atsuo, SAKIHAMA Yasuko, TAMAI Yutaka, MATSUURA Hideyuki

   

  We investigated rhizo-biosystems that enable to mitigate adverse soils in Kalimantan, Indonesia. Burkholderia sp. strain A-KA that had been isolated from the rhizosphere of Imperata cylindrica grown in medium-strongly acidic peatland showed a growth-helper activity toward other rhizosphere bacteria, such as Sphingomonas sp. Burkholderia mimosarum isolated from rhizosphere of paddy rice tolerant to acid-sulfate soil suppressed tropolone production of B. plantarii, a bacterium causative of rice blight disease, while promoted growth of diverse root-and seed-epiphytic bacteria. Among rhizobacteria that had isolated from dipterocarpous sapling adapting to polyphenol-rich tropical peat soil, pyrogallol-containing plant polyphenols activated Burkholderia unamae CK-43B to degrade indole and some other N-heterocyclic aromatic compounds. In the coralloid root symbiotic systems between Cycas revoluta root and a nitrogen-fixing cyanobacterium Nostoc punchiforme, a diacylglycerol was found to be the principle of hormogoniu-inducing factor on the cyanobacterium necessary to its host-recognition. Also, we successfully isolated and characterized signal compounds from a rhizobacterium Pseudomonas jessenii strain EC-S101 isolated from spinach root and from a rhizosphere fungus Trichoderma virens strain PS1-7 isolated from paddy root. In the rhizosphere, nitrous oxide emitting bacteria in tropical peat soil were missing their nitrous oxide reductase (N2OR) genes, and affected its denitrification by several secondary metabolites of plants
• Optimization of tropical peatland management based on carbon flow control

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2007 -2010 

  Author : INOUE Takashi, HIRANO Takashi, HATANO Ryusuke, TANI Hiroshi, SAITOU Hideyuki, TAMAI Yutaka, OSAKI Mitsuru, HATA Hiroshi, HASHIDOKO Yasuyuki, URAKI Yasumitsu, TAWARAYA Keitaro, HARAGUCHI Akira, ABE Ryuichiro

   

  Tropical peat land is a huge carbon sink involving an ecosystem that is very fragile but rich in biodiversity. This study deployed on establishment of measures for optimum land use and land management based on the viewpoint of control of carbon flow in tropical peatland. Prevention of peat fire, restoration of devastated land, sustainable bioproduction, and the reduction of environment load are the special interest that is rendered for the approach.
• Creation of cellulosic materials mimicking secondary wall structure in tree cell wall

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2006 -2008 

  Author : URAKI Yasumitsu, HIRAI Takuro, TAMAI Yutaka, KISHIMOTO Takao, SUGIYAMA Junji

   

  樹木細胞壁の二次壁の特徴は、他の壁組織に比べ多量に存在するリグニンとその化学構造である。本研究では、二次壁模倣材料の創出を目的に、二次壁リグニン模倣高分子を創製して、その物性を明らかにした。さらに、ハニカムパターン化セルロースにリグニンを吸着させて二次壁模倣セルロース材料を創製して、その物性解析からリグニンが高湿度における細胞壁の強度低下を抑制することを見出すと共に、木材成分のみで高強度材料を創出できることを明らかにした。
• Investigation of functional rhizo-biocomplex on highly adverse soil-adapting plants and application of the functional rhizo-biocomplex to agro-technology.

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2004 -2007 

  Author : HASHIDOKO Yasuyuki, TAMAI Yutaka, HARAGUCHI Akira, MATSUURA Hideyuki, IWAHASHI Hitoshi, TAWARAYA Keitarou

   

  Using local peat soil from Central Kalimantan, Indonesia, a saprophytic soil fungus Penicillium sp. Isolate Y-1 from X. complanata seedbed was tested its seed-germination promotion activity. The seeds germinated well by means of inoculation with Y-1 fungus, but the resulting seedlings were all died after one month-incubation in the local peat soil bed. Only when the supernatant of the local soil suspension without sterilization was further inoculated to the seedbeds, the germinated seedlings that had been inoculated with Y-1 resulted in survival and normal growth of the seedlings over 6 month. This suggested that saprophytic fungi stimulate seed germination, while some soil bacteria provide nutrients to the germinated seedlings. On the other hand, in Siberian Taiga forest bed soil, oligotrophic Burkholderia and Pseudomonas occupied soil microflora, and they showed a relatively high acetylene reduction activity at 10-15℃,under a lower concentration of carbon source (0.02-0.05%). Including medium pH, these soil bacteria were highly adapted to culture conditions agreeable to the permafrost soil, so that physicochemical conditions similar to activated permafrost soil in summer seasons resulted in relatively higher nitrogen-fixing activity. Moreover, gellan gum as gel matrix allowed the bacteria to show maximal nitrogen-fixing potential. Under a field condition of newly accumulated volcanic ash soil accumulated extreme soil land in Mt. Usu, Hokkaido, the land allowed pioneer plants to possess mycorrhizal symbionts and grew dominantly. Particularly, those of willow tree saplings constitutively possessed ectomycorrhizal fungi, while herbivorous weeds, except horsetail and rasp, allowed symbiosis with arbuscular mycorrhizal fungi. Thus, it was found that pioneer plants distributing throughout fresh volcanic ash soil in Mt. Usu were dependent on mycorrhizal infection.
• 国際共同研究シベリアカラマツ産地試験実施に向けた企画調査

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2005 -2005 

  Author : 高田 克彦, 船田 良, 栗延 晋, 長坂 壽俊, 吉丸 博志, 玉井 裕

   

  本研究は、シベリアカラマツに関する国際共同研究実施に向けた国内外の研究者9名(研究協力者2名を含む)による企画研究である。 研究代表者の高田は研究協力者であるOwe Martinsson(SLU, Sweden)を通じてフランス、アイスランド、ノルウェー、フィンランド、ロシア、中国、カナダ、アメリカ等のカラマツ属植物研究者との間にネットワークを構築した。その結果はシベリアカラマツに関するホームページ「SIBLARCH : http://www.siblarch.net/」の開設に結びついた。 研究代表者の高田及び研究分担者の船田(東京農工大)及び長坂(森林総合研究所)は平成17年9月並びに11月に研究協力者であるOwe Martinsson(SLU, Sweden)を訪問してスウェーデンに設定されているシベリアカラマツ産地試験林の見学を行った。また、日本におけるシベリア産地試験林設置に伴う経費、シベリアカラマツ産地試験林を利用した国際共同研究に関する具体的な内容に討議した。これらの討議内容をもとに他の研究分担者と平成18年度以降の国際共同研究に関する協議を行った。 研究代表者の高田はこれらの活動・協議の結果をもとに、平成17年11月に国際共同研究「産地試験林を利用したシベリアカラマツの炭素固定能力の評価」について科学研究費基盤研究(B)海外学術調査に申請するに至った。この申請研究は本企画研究のメンバーである船田(東京農工大学)と研究協力者であるOwe Martinsson(SLU, Sweden)を含む研究組織による国際共同研究である。
• Creation of artificial cell wall by mimicking the process of natural cell wall formation

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2003 -2005 

  Author : URAKI Yasumitsu, TAKABE Keiji, FUKUSHIMA Kazuhiko, KONDO Tetsuo, FUNADA Ryo, TAMAI Yutaka

   

  An aim of this research is to clarify the construction mechanism of tree cell wall that had the hierarchical structure from molecular level to tissue level. In addition, our objective is to create an artificial cell wall by mimicking the formation process of natural wood cell wall on the basis of the results of former subjects. In this research project, we obtained experimental results and conclusions for five subjects. Conclusion 1.Xylan is a key hemicellulose for lignification. Conclusion 2.This finding for ConClusion 1 was supported by physicochemical analysis of the interaction between hemicelluloses and lignification-related compounds. These analyses were carried out on an apparatus based on the surface plasmon resonance. Conclusion 3.We clarified solution behavior of LCC in water, such as interaction of solvent, self-assembly of LCC molecules and formation of hydrophobic domain in the self-aggregates. We proposed LCC functions in the wood from these results. Conclusion 4.we developed a new analysis method, Time of Flight・Secondary Ion Mass spectroscopy (ToF-SIMS), for lignin structure, and artificial lignin polymer, which was merely comprised of β-O-4, as a lignin model for NMR assignment. Conclusion 4 We elucidate the cell wall formation at the cell level in relation to cell-supported proteins, microtubles and actin in addition to tissue formation. Conclusion 5.we developed a methodology to create artificial cell wall on the basis of findings obtained in this study. The artificial cell wall backbone was fabricated by the conversion of bacterial cellulose to honeycomb-patterned material. The conversion was carried out by the control of the movement of cellulose-producing bacteria.
• 国際研究集会『Larix 2004』に向けた企画調査 ニホンカラマツを対象にした研究成果の再評価と新たな研究課題の提示

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2003 -2003 

  Author : 高田 克彦, 玉井 裕, 栗延 晋, 長坂 壽俊, SZMIDT Alfred, 安江 恒

   

  本研究の目的は2004年9月に日本で開催される国際研究集会『Larix2004』について研究内容面からの企画準備を行うことである。具体的には、上記研究集会にむけて専門分野の異なる研究者が現在までに国内外で行われてきたニホンカラマツを対象にした研究の学術的意義を再評価し、そこでの問題点の抽出と新たな研究課題を提示することである。以下、研究実績を時系列に示す。 平成15年5月、交付内定通知を受けて、研究費の配分を行うとともに、研究代表者及び研究分担者間で主に電子メールによって関連研究領域間での調整を行い、境界領域の研究課題提示に向けた話し合いを行った。 平成15年6月、京都において第1回課題検討会議を行った。会議においてそれぞれの研究分担者が担当する研究分野を以下のように決定した。全体総括:高田、次代検定林分野:栗延、産地試験分野:長坂、木材強度分野:小泉、木材組織構造及び利用分野:安江、分子生物学分野:Szmidt、森林生態学分野:木佐貫、特用林産物分野:玉井。 6月の課題検討会議以降、各研究分担者はそれぞれの研究分野において過去実施された研究・調査に関する文献収集を行う。 平成15年12月、秋田県立大学・木材高度加工研究所において第2回課題検討会議を行った。会議において研究分野の境界領域の取り扱い、最終報告所(英文)の書式、最終報告所の配布方法等について討議を行った。 平成16年3月、研究分担者より各研究分野において行われた過去の研究・調査に関する取りまとめが研究代表者のもとに送付され、研究代表者によってコンパイルされた。 現在、今年9月に行われる国際研究集会において参加者への配布資料として再編集中である。
• Study on the vegetation-enbironment interaction in the rooting zone of disturbed area.

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2000 -2003 

  Author : YAJIMA Takashi, MIYAMOTO Toshizumi, KIKUCHI Shun-ichi, TAMAI Yutaka

   

  This study was carried out to elucidate the vegetation-environment interaction in the rooting zone of plants growing on heavily disturbed area for the purpose of applying the relationships to revegetation works. To explain the vegetation-environment interaction, we selected the disturbed areas such as Mt.Usu for volcanic disturbed site which erupted in 2000, river side of Satsunai-gawa for riparian disturbed area, and mountain slopes of Hidaka district for large scale erosion disturbance area. The survey were conducted in each site for the disturbance resume, revegetation process, growth analysis of invaded trees, mycorrhiza infection to the plant roots and physical and chemical site conditions. On the volcanic disturbed site around the new craters of Mt.Usu, early stage of vegetation recovery process was recorded and ectomycorrhiza (ECM) or arbuscular mycorrihza (AM) types which infected to the plant roots were investigated. On the disturbed area of river sides, we investigated the stand dynamics and growth characteristics of Chosenia arbutifolia in addition to the nutrient condition of riparian zone. Further, the infection ratio, the types of ECM and seasonal dynamics of ECM infection on the roots of Salix sachalinensis seedlings were surveyed. And also, we investigated the culture medium of tree seedlings which expected to use for vegetation works. We succeeded in artificial infection of ECM in semi-open condition. These are the certain progress for the application to the advanced works of the vegetation-enbironment interaction systems in the rooting zone.
• Radial growth and cell wall structure of trees grown under elevated carbon dioxide concentrations

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 1999 -2001 

  Author : FUNADA Ryo, TAMAI Yutaka, SANO Yuzou, KOIKE Takayoshi, MARUYAMA Yutaka

   

  We estimated long-term effects of elevated carbon dioxide concentrations [CO_2] on physiological and anatomical characteristics of trees, namely the stem growth, wood structure and characteristics of photosynthesis. Seedlings of larch (Larix sibirica and Larix kaempferi) and white birch (Betula platyphylla var. japonica) trees were grown in growth chambers under two [CO_2], ambient (360 ppm) and elevated (720 ppm), and with high or low levels of nutrients for one-three growing seasons. Elevated [CO_2] had no significant effects on stem height and stem diameter. However, the stem height and stem diameter were enhanced by the high level of nutrients and these increases were stimulated by elevated [CO_2]. Annual ring widths, cell numbers and cell diameters tended to increase, whereas cell wall thickness tended to decrease slightly in response to elevated [CO_2] , By contrast, there were no statistically significant differences in the relative area of cell wall, which was closely related to specific gravity of wood, indicating that elevated [CO_2] had few effects of changes in wood quality. In conclusion, there is no obvious enhancement in the capacity of carbon fixation by elevated [CO_2]. However, changes in the temporal pattern of stem growth and in anatomical features of the stem would occur under elevated [CO_2]. Although net assimilation rate under which seedlings grew was higher in elevated [CO_2] than in ambient [CO_2], little enhancement of photosynthesis rate of whole crown under elevated [CO_2] was observed because of the smaller specific leaf area and the acclimation of photosynthetic characteristics of leaves to [CO_2] which seedling grew. Such acclimation of photosynthesis was closely related to the decrease in amounts of soluble proteins and Rubisco, which is a key enzyme of photosynthesis, in leaves.
• 有毒キノコ種の分子マーカーによる識別

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 1999 -2000 

  Author : 玉井 裕

   

  1.菌株の収集 北海道内において中毒例の報告されている種、またはその近縁種を採取し、形態観察による種の同定、標本作製および菌株分離を行った。採取したキノコの系統数は以下の通りである。 ベニタケ属(6種15系統)、チチタケ属(5種18系統)、テングタケ属(3種15系統)、カヤタケ属(3種11系統)、クリタケ属(3種15系統)、スギタケ属(3種9系統)、アセタケ属(2種5系統)、イッポンシメジ属(3種12系統)、イグチ属(2種6系統)、カラカサタケ属(2種4系統)、ヌメリイグチ属(4種12系統)、モエギタケ属(2種5系統)、フウセンタケ属(4種8系統)、サマツモドキ属(2種7系統)、フクロタケ属(3種6系統)、ウラベニガサ属(3種8系統)、以上50種156系統。 2.分子マーカーの検索 上記において採取したキノコ種を、属内において有毒種と可食(または無毒)種とを識別することを目的として、PCR用テンプレートDNAの抽出条件および、PCR法によるリボソームRNA遺伝子のIGS領域の増幅条件を検討した。テンプレートDNAは、生子実体、アルコール浸漬標本および凍結乾燥標本のいずれからもTEバッファー中で100℃、10分間の煮沸抽出処理により調製可能であることが明らかとなった。得られたテンプレートを用いてIGS領域の増幅を行い、500〜700ベースの増幅物を得たが、非特異的なバンドの出現が幾つかの系統に認められた。IGS領域長には特に明確な種特異性は認められなかった。更に、IGS領域PCR増幅物に対して、DdeI、AluI等の制限酵素を用いてRFLPパターンを取得し、種間比較を行ったが、供試菌株群については単独酵素処理による有毒種の識別は困難であった。属毎に供試菌株を増やして、生物学的種との対応も考慮しつつ、更に検討してゆく必要性があると考えられた。
• 担子菌遺伝子の発現メカニズムの解明

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 1998 -1999 

  Author : 三浦 清, 玉井 裕

   

  1) 子実体形成に関わる遺伝子の単離 エノキタケ(Flammulina velutipcs)について子実体誘導処理後7日目の菌糸体からcDNAライブラリーを作成し、誘導処理前の菌糸体との間でディファレンシャルスクリーニングを行った結果、誘導処理後7日目の菌糸体で特異的に発現している多くの遺伝子のcDNAクローンを得た。これらの遺伝子のノーザン解析、cDNAシーケンス、ゲノムシーケンスを行い、遺伝子の解析を行った。またコードしているアミノ酸についてホモロジー検索を行ったところ、ハイドロフォビン様タンパク質および酸化還元酵素様タンパク質との類似性が確認されたが、他の遺伝子はホモロジーを有するものが確認できなかった。 2) 遺伝子導入系の開発 担子菌であるエノキタケの形質転換系を確立するために、構造的に強く発現しているGPD(グリセロールアルデヒド-3-リン酸デヒドロゲナーゼ)遺伝子のプロモーター領域とターミネーター領域を用いる実験系の構築を検討した。 スエヒロタケ(SchizophyHum commune)において既に報告されている塩基配列を参考にしてPCRプローブを作成し、このプローブを用いてエノキタケのゲノムライブラリーより、GPD遺伝子を含むゲノムクローンを単離した。その制限酵素地図を作成し、GPD遺伝子を含む部分をサブクローニングし、これを導入系ベクターに挿入し、レポーター遺伝子としてルシフェラーゼ遺伝子をを用いてそのプロモーター活性を測定した。
• Exudation Mechanism of Tree Sap

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 1998 -1999 

  Author : TERAZAWA Minoru, SHIBUYA Masao, FUNADA Ryo, TAKAHASHI Kunihide, SANO Yuzou, TAMAI Yukata

   

  Sap exudation : The period of the starting point of the sap exudation of birch trees coinsides with that the earth temperatures become above 0℃. The amount of the sap exudated in the one season corelates with the atomospheric temperatures and the change in the amount of sap exudated within a day corelates with the changes in atomospheric temperatures. Production in the leaves in a summer influences the amount of sap exudation in the following spring. Water distribution : The sap in the tracheids disappears gradually towards winter and disappear completely in the period just before the sap exudation starts by the repetition of freezing of the xylem and its re-freezing. The recovery of the cavitation seems to be derived by the pressures in the roots. Actually, the swelling of the roots during the sap exudation process was observed. The process of the refilling of the sap in the tracheids of the xylem was photographically recorded by Cryo-SEM techniques. The osmotic pressures in the sap of xylem tracheids and the function of the water pumping proteins in roots and trunks are the next targets to be investigated.
• 高度攪乱立地における微生物フロラの動態解明と緑化への応用

  Date (from‐to) : 1999
• The Tree Growth and Water Relation of Boreal Forest

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 1996 -1997 

  Author : TERAZAWA Minoru, TAMAI Yutaka, SANO Yuzo, FUNADA Ryou, SAKAI Kenji, OHTANI Jyun

   

  The Tree Growth and Water Relation in Boreal Forest The tree growth and water relation in boreal forests were investigated. Strain gages were glued in the tangential direction of the surface of the inner bark of several trees. Diurnal change in the tangential strain were measured throughout the seasons. 1) In winter in the boreal forests, the water in the tranks of trees frozen into ice. The diurnal change of the strain during this period coinsided with the shrinkage and swelling of the ice following the change of air temperature under zero degrees centigrate. The movement was the largest in a yaer. 2) In early spring, shirakamba birch exudated sap through a hole drilled on the trank. Sap exudation continued for one month and stopped just on time when flowers and leaves opened. The diurnal change of the strain was the lowest in the year. Trees seemed to keep a positive pressure throughout this period for sending the sap up to the buds of flowers and leaves for their growth and opening. 3) In spring and summer after the leaf opening, tree growed. The diurnal change of the strain in this period varied inversely with the change observed in the winter season. Namely, the trank started to shrink when air temperature started to rise after sun rise and shrinked continuously till noon and released the shrinkage when air temperature started to fall down toward evening. During night the shrinkage was revovered and swelled a little more than the starting point of the day before. The change seemed to coinside with the balance of the activities between transpiration of the leaves and water absorption from the roots. The changes were higher in sunny days because of higher transpiration and photosynthesis activities and were lower in rainy days with their lower activities. 4) The growth curve of the trank was drawn as an integration of the difference between the shrinkage and the release of the shrinkage and following swelling. A maximum of the growth rate was observed on the end of July and the rate decreased gradually toward defoliation.
• 熱帯産きのこ資源の開発
• シラカンバ樹液の溢出メカニズム
• 担子菌の染色体解析
• Development of mushroom resources in tropical forest
• Mechanism of Birch Sap Exudation
• Chromosomal Analysis of Basidiomycetes