Sun Cong, Xu Lin, Yu Xiao-Yun, Zhao Zhe, Wu Yue-Hong, Oren Aharon, Wang Chun-Sheng, Xu Xue-Wei
1College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, PR China.
2Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, PR China.
Int J Syst Evol Microbiol. 2018 Dec;68(12):3856-3862. doi: 10.1099/ijsem.0.003073. Epub 2018 Oct 16.
Two Gram-stain-negative, strictly aerobic, non-motile, non-spore-forming, rod-shaped bacteria, designated as SY3-15and SY3-13, were isolated from a seawater sample of the South China Sea. Colonies were 0.5-1.0 mm in diameter, smooth, circular, convex and translucent after growth on marine agar at 37 °C for 3 days. The strains were found to grow at 20-50 °C (optimum, 42 °C), pH 6.0-8.5 (optimum, pH 6.5-7.5) and with 0.5-6.0 % (w/v) NaCl (optimum, 1.5-2.0 %). Chemotaxonomic analysis showed the sole respiratory quinone to be ubiquinone-10, the major fatty acids (>10 %) were C16 : 0 3-OH, C19 : 0cyclo ω9c, C18 : 1 3-OH and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), and the polar lipids were phosphatidylglycerol, two unidentified aminolipids and three unidentified lipids. The DNA G+C content was 67.2-67.4 mol% calculated by genome. The 16S rRNA gene sequences of strains SY3-15 and SY3-13 were identical and related to the genus Lutibaculum with a similarity of 92.1 %. The 16S rRNA gene phylogenetic trees reconstructed with neighbour-joining, maximum-parsimony and minimum-evolution methods showed that the strains constituted a deep and separated branch from other families of Alphaproteobacteria, and the phylogenetic trees based on concatenated 163 protein sequences from genome sequences showed that the clade in which strains SY3-15 and SY3-13 located was separated from the clade of the other orders of Alphaproteobacteria, indicating it may represent a novel family of a novel order. Based on their phenotypic properties and their phylogenetic distinctiveness, we propose strains SY3-15 (=MCCC 1K03467=KCTC 62335) and SY3-13 (=MCCC 1K03466=KCTC 62329) to represent a novel species of a novel genus with the name Minwuia thermotolerans gen. nov., sp. nov., and we propose Minwuiaceae fam. nov. and Minwuiales ord. nov. with Minwuia as the type genus.
从中国南海海水样本中分离出两株革兰氏阴性、严格需氧、无运动性、不形成芽孢的杆状细菌，分别命名为SY3-15和SY3-13。在37 °C的海洋琼脂培养基上培养3天后，菌落直径为0.5-1.0 mm，光滑、圆形、凸起且半透明。发现这些菌株在20-50 °C（最适温度为42 °C）、pH 6.0-8.5（最适pH为6.5-7.5）和0.5-6.0 %（w/v）NaCl（最适浓度为1.5-2.0 %）的条件下生长。化学分类分析表明，唯一的呼吸醌为泛醌-10，主要脂肪酸（>10 %）为C16 : 0 3-OH、C19 : 0cyclo ω9c、C18 : 1 3-OH以及总和特征8（C18 : 1ω7c和/或C18 : 1ω6c），极性脂质为磷脂酰甘油、两种未鉴定的氨基脂质和三种未鉴定的脂质。通过基因组计算，DNA G+C含量为67.2-67.4 mol%。菌株SY3-15和SY3-13的16S rRNA基因序列相同，与Lutibaculum属相关，相似度为92.1 %。用邻接法、最大简约法和最小进化法重建的16S rRNA基因系统发育树表明，这些菌株构成了一个与α-变形菌纲其他科深度分离的分支，基于基因组序列中163个串联蛋白质序列构建的系统发育树表明，菌株SY3-15和SY3-13所在的分支与α-变形菌纲其他目的分支分离，表明它可能代表一个新目的新科。基于它们的表型特征和系统发育独特性，我们提议将菌株SY3-15（=MCCC 1K03467=KCTC 62335）和SY3-13（=MCCC 1K03466=KCTC 62329）代表一个新属的新物种，命名为耐热闽武菌（Minwuia thermotolerans），新属名闽武菌属（Minwuia），新种名耐热闽武菌（Minwuia thermotolerans），并提议建立闽武菌科（Minwuiaceae）新科和闽武菌目（Minwuiales）新目，以闽武菌属为模式属。
