State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, PR China.
Marine College, Shandong University, Weihai, Shandong 264209, PR China.
Int J Syst Evol Microbiol. 2020 Sep;70(9):5001-5011. doi: 10.1099/ijsem.0.004370.
is widespread and ecologically important in various anoxic environments. However, the portion of culturable bacteria within this phylum is quite low and, in fact, there is only one currently described species. In this study, a novel anaerobic, non-motile, coccoid, Gram-stain-negative bacterial strain, designated S-5007, was isolated from surface marine sediment. The 16S rRNA gene sequence was found to have very low 16S rRNA gene sequence similarity to the nearest known type strain, L21-Fru-AB (84.9 %). The taxonomic position of the novel isolate was investigated using a polyphasic approach and comparative genomic analysis. Phylogenetic analyses based on 16S rRNA genes and genomes indicated that strain S-5007 branched within the radiation of the phylum . Different from the type strain, strain S-5007 can grow under microaerobic conditions, and the genomes of strain S-5007 and the other strains in its branch have many more antioxidant-related genes. Meanwhile, other different metabolic features deduced from genome analysis supported the separate evolution of the proposed class (strain S-5007 branch) and L21-Fru-AB. Based on phylogenetic and phenotypic characterization studies, gen. nov., sp. nov. is proposed with S-5007 (=MCCC 1H00402=KCTC 15876) as the type strain, as the first representative of novel taxa, ord. nov., fam. nov. in class. nov.
它在各种缺氧环境中广泛存在且具有重要的生态意义。然而，该门中可培养细菌的比例相当低，实际上目前仅描述了一个物种。本研究从海洋表层沉积物中分离到一株新型的厌氧、非运动、球形、革兰氏阴性细菌，命名为 S-5007。16S rRNA 基因序列与最近已知的模式菌株 L21-Fru-AB（84.9%）的 16S rRNA 基因序列相似度非常低。采用多相分类法和比较基因组分析对新型分离株的分类地位进行了研究。基于 16S rRNA 基因和基因组的系统发育分析表明，菌株 S-5007 分支在该门的辐射区内。与模式菌株不同，菌株 S-5007 可以在微需氧条件下生长，并且菌株 S-5007 和其分支中的其他菌株的基因组中有更多与抗氧化相关的基因。同时，从基因组分析中推断出的其他不同代谢特征也支持所提议的类（菌株 S-5007 分支）和 L21-Fru-AB 的独立进化。基于系统发育和表型特征研究，建议建立一个新属、新种，即 S-5007（=MCCC 1H00402=KCTC 15876）为模式菌株，作为新型分类单元的第一个代表，即 纲 nov.，目 nov.，科 nov.，在新建立的 门 nov.中。
