Ueda K, Ohno M, Yamamoto K, Nara H, Mori Y, Shimada M, Hayashi M, Oida H, Terashima Y, Nagata M, Beppu T
Department of Applied Biological Sciences, Nihon University, Fujisawa, Japan.
Appl Environ Microbiol. 2001 Sep;67(9):3779-84. doi: 10.1128/AEM.67.9.3779-3784.2001.
Symbiobacterium thermophilum is a tryptophanase-positive thermophile which shows normal growth only in coculture with its supporting bacteria. Analysis of the 16S rRNA gene (rDNA) indicated that the bacterium belongs to a novel phylogenetic branch at the outermost position of the gram-positive bacterial group without clustering to any other known genus. Here we describe the distribution and diversity of S. thermophilum and related bacteria in the environment. Thermostable tryptophanase activity and amplification of the specific 16S rDNA fragment were effectively employed to detect the presence of Symbiobacterium. Enrichment with kanamycin raised detection sensitivity. Mixed cultures of thermophiles containing Symbiobacterium species were frequently obtained from compost, soil, animal feces, and contents in the intestinal tracts, as well as feeds. Phylogenetic analysis and denaturing gradient gel electrophoresis of the specific 16S rDNA amplicons revealed a diversity of this group of bacteria in the environment.
嗜热共生菌是一种色氨酸酶阳性嗜热菌，仅在与其共生细菌共培养时才能正常生长。对16S rRNA基因（rDNA）的分析表明，该细菌属于革兰氏阳性菌组最外层位置的一个新的系统发育分支，未聚类到任何其他已知属。在此，我们描述了嗜热共生菌及相关细菌在环境中的分布和多样性。利用热稳定色氨酸酶活性和特异性16S rDNA片段的扩增有效地检测嗜热共生菌的存在。用卡那霉素富集提高了检测灵敏度。含有嗜热共生菌种的嗜热菌混合培养物经常从堆肥、土壤、动物粪便、肠道内容物以及饲料中获得。对特异性16S rDNA扩增子的系统发育分析和变性梯度凝胶电泳揭示了该组细菌在环境中的多样性。
