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Characterization of low temperature microorganisms inhabiting in moss in Polar Regions on species identification, enzyme production and cold resistance.

极地苔藓中栖息的低温微生物的物种鉴定、酶生产和抗寒性特征。

基本信息

批准号：
16510181
负责人：
YUMOTO Isao
金额：
$ 2.6万
依托单位：
National Institute of Advanced Industrial Science and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2007
项目状态：
已结题

项目摘要

Low temperature microorganisms especially plant parasitic fungi inhabiting in Polar Regions were characterized on species identification, enzyme production and cold resistance.Six Trichoderma strains isolated from Spitsbergen Island in 2002 were examined on species identification and enzyme production. The all strains were identified as Trichoderma polysporum by their morphology in a cultivation condition and sequences of rDNA ITS regions. Three representative strains of the Arctic T. polysporum were tested on production of extracellular enzymes. The all strains were secreted xylanase and polygalacturonase in a sugar beet extract liquid medium. Among these enzymes, a polygalacturonase (PG) was purified. The purified PG from T. polysporum strains isolated from Germany was used as comparison. PG from the Arctic strain showed optimum activity at 40℃ and 14 to 47% of maximum even at 0℃. While PG from the German strain showed optimum activity at 50℃ and 0 to 4% of maximum at 0℃. The results indicate that the Arctic T. polysporum strains are potential source of a cold active PG.Pythium spp. from Spitsbergen Island, Greenland and King George Island were examined on species identification. The total 314 isolates were categorized as unknown Pythium species 1 to 5. Most of them showed pathogenicity to a moss (Sanionia uncinata) and wheat leaves in an in vitro inoculation test. Their optimum temperatures for hyphal growth on an agar culture were 22 to 28℃. At least one isolate of Arctic Pythium strains has greater resistance to freezing than a strain of its morphologically related Pythium speices. These results suggest unique species of Pythium inhabiting in Polar Regions. During this investigation, Pythium selective media for isolation them from natural environmental conditions were developed.A smut fungus on Polygonum viviparum in Svalbard, Norway was identified as Microbotryum bistortarum during this study.

对极地地区的低温微生物特别是植物寄生真菌进行了种类鉴定、产酶和抗寒性研究，并对2002年从斯匹次卑尔根岛分离到的6株木霉菌进行了种类鉴定和产酶研究。根据培养条件下的形态学特征和rDNA ITS区序列分析，将所有菌株鉴定为多孢木霉（Trichoderma polysporum）。北极T.多孢菌的胞外酶的生产进行了测试。所有菌株在甜菜提取液培养基中都能分泌木聚糖酶和多聚半乳糖醛酸酶。在这些酶中，纯化了多聚半乳糖醛酸酶（PG）。从T.分离自德国的多孢子菌菌株用作比较。北极株PG在40℃时活性最高，0℃时仍为最高活性的14 ~ 47%。德国菌株PG的最适温度为50℃，0℃时为最大值的0 ~ 4%。结果表明，北极T.多孢霉菌株是潜在的冷活性PG源。从斯匹次卑尔根岛、格陵兰岛和乔治王岛采集了100只白蛉，进行了种鉴定。共314个分离物被归类为未知腐霉种1至5。在离体接种试验中，大多数菌株对藓类（Sanionia uncinata）和小麦叶片表现出致病性。菌丝在琼脂培养基上生长的最适温度为22 ~ 28℃。至少有一种北极腐霉菌株的分离株比其形态学上相关的腐霉种的菌株具有更大的抗冻性。这些结果表明，独特的物种腐霉栖息在极地地区。通过对挪威斯瓦尔巴特群岛珠芽蓼（Polygonum viviparum）黑粉病菌的分离鉴定，确定该黑粉病菌为微孢霉（Microbotryum bistortarum）。