从西南印度洋热液区沉积物样品中分离纯化获得一株中度嗜热产芽孢杆菌,命名为M6.菌株M6为革兰氏阳性菌,短杆状,可成对.菌株M6的生长温度为35-65℃(最适生长温度60℃),生长pH为6.5-8.5(最适生长pH为7.0-8.0),生长NaCl质量分数为0-4%(最适NaCl质量分数为2%),生长盐度为0-80人工海水(最适盐度为40).16S rRNA基因相似性分析表明,菌株M6属于不产氧芽孢杆菌属(Anoxybacillus),与Anoxybacillus rupiensis菌株同源性最高,达99%;但16S-23S rDNA间隔区PCR扩增分析表明,该菌与同属菌株有较大差异.通过以上形态学、生理特征以及分子生物学鉴定,认为菌株M6为不产氧芽孢杆菌属的菌株.另外,菌株M6可分泌胞外高温淀粉酶.菌株M6胞内含有内生质粒,其大小约为10 kb,命名为pAB01.
A thermophilic spore-forming strain M6 was isolated from the sediments of Southwest Indian Ocean hydrothermal vents.Strain M6 was Gram-positive,rod-shaped,occurring in pairs or rods.Growth was observed between 35 and 65 ℃(optimum 60 ℃),at pH 6.5 to 8.5(optimum pH 7.0 to 8.0),at 0 to 4%(by mass) NaCl(optimum 2%NaCl) and 0 to 80 artificial sea salts(optimum 40).On the basis of 16S rRNA gene sequence similarity,strain M6 was shown to be related most closely to Anoxybacillus rupiensis,but 16S to 23S rDNA internally transcripbed spacer polymorphism PCR showed variation between isolate M6 and related species.The microorganism produced an extracellular constitutive amylolytic activity.One plasmid,named pAB01,was isolated from strain M6 with a length of about 10 kb.