南极长城湾海绵共附生可培养细菌多样性研究

Diversity of sponge-associated culturable bacteria,Great Wall Bay,Antarctica

研究了南极长城湾潮间带海绵共附生可培养细菌多样性及其疑似新种应用有利于放线菌生长的选择性培养基ISP2从长城湾海绵动物组织中分离出120株细菌,基于这些菌株的16S rRNA基因序列开展系统发育分析。结果显示,所分离菌株隶属于三个细菌门五大类群的11个目、22个属,表明长城湾海绵共附生细菌的种属分布较广、多样性非常高。其中红球菌Rhodococcus属占优势,另外包含α-变形菌纲Puniceibacterium属、放线菌门Aeromicrobium属、β-变形菌纲Limnobacter属等罕见种属。16S rRNA基因序列同源性比对分析表明,菌株HM145与Rhodococcus属模式种Rhodococcus qingshengii具有最高序列相似性97.0%,菌株HQ09与Puniceibacterium antarcticum有96.9%的最高相似性,为2株疑似新种,其分类地位和种水平上的分类学研究有待开展多相分类进行鉴定。

This paper studied the diversity of intertidal sponge-associated culturable bacteria and suspected novel species in the Great Wall Bay,Antarctica. 120 bacterial strains were isolated from three unidentified sponge samples in the intertidal sediment by using the selective medium ISP2 which was beneficial to the growth of actinomycetes. Phylogenetic analysis based on 16 S rRNA gene sequences showed these strains could be classified into 11 orders,22 genera in 3 phyla and 5 taxa,indicating that these culturable spongeassociated bacteria had a wide genus distribution with high diversity. In addition,the Rhodococcus strains were dominant and contained the rare strains from genus Puniceibacterium,Limnobacter and Aeromicrobium.Analysis on the homology alignment of 16 S rRNA gene sequences revealed that strain HM145 had the highest similarity of 97. 0% with the type strain Rhodococcus qingshengii from genus Rhodococcus,and strain HQ09 had the highest similarity of 96. 9% with the type strain Puniceibacterium antarcticum. These data indicated that strain HM145 and HQ09 would be the suspected novel species. However,their classification status and polyphasic taxonomy at the level of species need to be further studied.