Liu Yang, Lai Qiliang, Shao Zongze
School of Municipal and Environmental Engineering, Harbin Institute of TechnologyHarbin, China.
State Key Laboratory Breeding Base of Marine Genetic Resources, Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, State Oceanic Administration, Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Key Laboratory of Marine Genetic Resources of Fujian ProvinceXiamen, China.
Front Microbiol. 2017 Jul 13;8:1321. doi: 10.3389/fmicb.2017.01321. eCollection 2017.
A multilocus sequence analysis (MLSA) was established and performed on the genus , including 23 strains isolated from diverse marine environments, with the aim of better differentiation of strains and species within this genus. The study was based on sequences of 16S rRNA gene and five protein-coding housekeeping genes, , and . In contrast to 16S rRNA gene-based tree that was unable to separate some species within this genus, each tree based on a single housekeeping gene and MLSA had consistently defined seven clades, corresponding to the five established ones and two novel ones. The digital DNA-DNA hybridization and average nucleotide identity analyses based on genome sequences of the representative strains reconfirmed the validity of the MLSA analysis, and recommended a 97.3% MLSA similarity as the soft species threshold and nine species representing the five known and four putative novel species. Two of the four new species were identified as sp. nov. (type strain TAW-CT134 = MCCC 1A10143 = LMG 29615) and sp. nov. (type strain 11.10-0-13 = MCCC 1A03502 = LMG 29618) by using a polyphasic taxonomic approach. Taken together, the newly established MLSA in this study first described the variability and phylogeny of the genus which contributes to better understanding its ecology and evolution.
建立了多位点序列分析（MLSA）并应用于该属，对从不同海洋环境中分离出的23株菌株进行分析，目的是更好地区分该属内的菌株和物种。该研究基于16S rRNA基因以及五个蛋白质编码看家基因（基因名称未给出）的序列。与基于16S rRNA基因的树无法区分该属内的一些物种不同，基于单个看家基因和MLSA构建的每棵树都一致地定义了七个进化枝，对应于五个已确定的进化枝和两个新的进化枝。基于代表性菌株基因组序列的数字DNA-DNA杂交和平均核苷酸同一性分析再次证实了MLSA分析的有效性，并推荐97.3%的MLSA相似性作为软物种阈值以及九个物种，其中包括五个已知物种和四个假定的新物种。通过多相分类学方法，四个新物种中的两个被鉴定为新种（模式菌株TAW-CT134 = MCCC 1A10143 = LMG 29615）和新种（模式菌株11.10-0-13 = MCCC 1A03502 = LMG 29618）。综上所述，本研究新建立的MLSA首次描述了该属的变异性和系统发育，这有助于更好地理解其生态学和进化。
