Zhong Zhi-Ping, Liu Ying, Wang Fang, Zhou Yu-Guang, Liu Hong-Can, Liu Zhi-Pei
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China.
University of Chinese Academy of Sciences, Beijing 100049, PR China.
Int J Syst Evol Microbiol. 2016 Jan;66(1):125-131. doi: 10.1099/ijsem.0.000687. Epub 2015 Oct 14.
Two Gram-stain-negative, catalase- and oxidase-positive, strictly aerobic, non-motile, moderately halophilic bacteria (strains X15M-6T and X15M-8T) were isolated from Lake Xiaochaidan, a salt lake in Qaidam basin, Qinghai Province, China. Cells of X15M-6T were rod-like or coccoid, 0.5-0.9 μm wide and 0.9-1.5 μm long; cells of X15M-8T were rods, 0.3-0.6 μm wide and 1.2-2.2 μm long. Growth was observed in the presence of 0.5-14.0 % (w/v) NaCl (optimum, 3.0 %) and at pH 6.5-10.0 (optimum, pH 7.0-7.5) for both. X15M-6T and X15M-8T grew at 10-35 °C (optimum, 20-25 °C) and 4-35 °C (optimum, 25 °C), respectively. Both contained iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids, phosphatidylethanolamine and an unknown lipid as the major polar lipids, and menaquinone MK-6 as the major respiratory quinone. The DNA G+C contents were 32.8 and 35.0 mol% for X15M-6T and X15M-8T, respectively. Phylogenetic trees based on 16S rRNA gene sequences showed that both strains belonged to the genus Psychroflexus and formed a separate lineage. In addition, strains X15M-6T and X15M-8T shared 96.8 % 16S rRNA gene sequence similarity and showed highest similarities to members of the genus Psychroflexus (92.7-93.5 and 91.8-93.1 %, respectively). Based on the above data, it is concluded that strains X15M-6T and X15M-8T represent two novel species of the genus Psychroflexus, for which the names Psychroflexus salis sp. nov. (type strain X15M-6T = CGMCC 1.12925T = JCM 30615T) and Psychroflexus planctonicus sp. nov. (type strain X15M-8T = CGMCC 1.12931T = JCM 30616T) are proposed.
从中国青海省柴达木盆地的小柴旦湖分离出两株革兰氏染色阴性、过氧化氢酶和氧化酶阳性、严格需氧、不运动、中度嗜盐的细菌（菌株X15M-6T和X15M-8T）。X15M-6T的细胞呈杆状或球状，宽0.5 - 0.9μm，长0.9 - 1.5μm；X15M-8T的细胞为杆状，宽0.3 - 0.6μm，长1.2 - 2.2μm。两株菌在0.5 - 14.0%（w/v）NaCl（最适浓度为3.0%）存在的条件下以及pH值为6.5 - 10.0（最适pH值为7.0 - 7.5）时均能生长。X15M-6T和X15M-8T分别在10 - 35°C（最适温度为20 - 25°C）和4 - 35°C（最适温度为25°C）下生长。两者均以异-C15:0、anteiso-C15:0和异-C17:0 3-OH作为主要脂肪酸，以磷脂酰乙醇胺和一种未知脂质作为主要极性脂质，以甲基萘醌MK-6作为主要呼吸醌。X15M-6T和X15M-8T的DNA G+C含量分别为32.8和35.0 mol%。基于16S rRNA基因序列构建的系统发育树表明，这两株菌均属于嗜冷弯曲菌属，并形成一个独立的分支。此外，菌株X15M-6T和X15M-8T的16S rRNA基因序列相似性为96.8%，与嗜冷弯曲菌属成员的相似性最高（分别为92.7 - 93.5%和91.8 - 93.1%）。基于上述数据，得出结论：菌株X15M-6T和X15M-8T代表嗜冷弯曲菌属的两个新物种，分别命名为嗜盐嗜冷弯曲菌（Psychroflexus salis sp. nov.）（模式菌株X15M-6T = CGMCC 1.12925T = JCM 30615T）和平浮游嗜冷弯曲菌（Psychroflexus planctonicus sp. nov.）（模式菌株X15M-8T = CGMCC 1.12931T = JCM 30616T）。
