Gao Peixin, Lu Huibin, Phurbu Dorji, Wu Qinglong, Xing Peng
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China.
Yunnan Key Laboratory of Plateau Geographical Process and Environmental Changes, Faculty of Geography, Yunnan Normal University, Kunming 650500, PR China.
Int J Syst Evol Microbiol. 2022 Dec;72(12). doi: 10.1099/ijsem.0.005653.
Thousands of lakes harbouring different characteristics (pH, salinity, temperature) are located on the Tibetan Plateau, and the mining of microbial resources inhabited in these lakes has great value. Two Gram-stain-negative, aerobic, rod-shaped, non-motile strains (LQ15W and AIY15W) were isolated from freshwater lakes on the Tibetan Plateau. Comparisons based on the 16S rRNA gene sequences showed that both strains LQ15W and AIY15W share 16S rRNA gene sequence similarities 98.4 % with Z0201, but only about 95.0 % with DSM 16537. The 16S rRNA gene sequence similarity between strains LQ15W and AIY15W was 98.9 %. The phylogenetic tree reconstructed based on 16S rRNA gene sequences also showed that strains LQ15W and AIY15W take Z0201 as their closest neighbour and these three strains form a tight cluster. In the phylogenomic tree, the genus was splited into two clusters by . Strains LQ15W, AIY15W and Z0201 still formed a close cluster, and DSM 16537 and CUG 91378 formed another cluster. The calculated OrthoANIu, average amino acid identity and digital DNA-DNA hybridization values among strains LQ15W, AIY15W, Z0201, DSM 16537 and CUG 91378 were less than 91.0, 92.9 and 42.1 %, respectively. The major respiratory quinones of both strains LQ15W and AIY15W were MK-7 (32 %) and MK-8 (68 %), and their major fatty acids were iso-C, C 9, summed feature 3 and summed feature 9. The predominant polar lipids of both strains were phosphatidylethanolamine, unidentified aminophospholipids, unidentified phospholipids and lipids. Strain AIY15W also contained phosphatidylglycerol and unidentified glycolipid. Considering the distinct phylogenetic relationships and chemotaxonomic characteristics between strains Z0201 and DSM 16537, it is proposed to reclassify into a novel genus gen. nov. as comb. nov., and strains LQ15W and AIY15W should represent two independent novel species of the genus , for which the names sp. nov. (type strain: LQ15W=CICC 24711=JCM 34222) and sp. nov. (type strain: AIY15W=CICC 24708=JCM 34612) are proposed.
青藏高原分布着数以千计具有不同特征（pH值、盐度、温度）的湖泊，对这些湖泊中蕴藏的微生物资源进行开采具有重大价值。从青藏高原的淡水湖中分离出两株革兰氏染色阴性、需氧、杆状、不运动的菌株（LQ15W和AIY15W）。基于16S rRNA基因序列的比较表明，菌株LQ15W和AIY15W与Z0201的16S rRNA基因序列相似性均为98.4%，但与DSM 16537的相似性仅约为95.0%。菌株LQ15W和AIY15W之间的16S rRNA基因序列相似性为98.9%。基于16S rRNA基因序列重建的系统发育树也显示，菌株LQ15W和AIY15W以Z0201为其最亲近的亲缘种，这三个菌株形成一个紧密的类群。在系统基因组树中，该属被 分为两个类群。菌株LQ15W、AIY15W和Z0201仍形成一个紧密的类群，而DSM 16537和CUG 91378形成另一个类群。计算得出，菌株LQ15W、AIY15W、Z0201、DSM 16537和CUG 91378之间的OrthoANIu、平均氨基酸同一性和数字DNA-DNA杂交值分别小于91.0%、92.9%和42.1%。菌株LQ15W和AIY15W的主要呼吸醌为MK-7（32%）和MK-8（68%），其主要脂肪酸为异-C、C9、总和特征3和总和特征9。这两个菌株的主要极性脂为磷脂酰乙醇胺、未鉴定的氨基磷脂、未鉴定的磷脂和脂类。菌株AIY15W还含有磷脂酰甘油和未鉴定的糖脂。考虑到菌株Z0201和DSM 16537之间明显的系统发育关系和化学分类特征，建议将 重新分类为一个新属 新属， 为新组合，菌株LQ15W和AIY15W应代表该属的两个独立新物种，为此提出名称 新种（模式菌株：LQ15W = CICC 24711 = JCM 34222）和 新种（模式菌株：AIY15W = CICC 24708 = JCM 34612）。
