Ekwe Adaeze Precious, Ahn Joong-Hyeon, Kim Seung Bum
Department of Microbiology and Molecular Biology, Chungnam National University, 99 Daehak-Ro, Yuseong, Daejeon 34134, Republic of Korea.
Int J Syst Evol Microbiol. 2017 Jul;67(7):2166-2170. doi: 10.1099/ijsem.0.001920. Epub 2017 Jul 3.
A yellow-pigmented, oxidase-positive, catalase-negative, Gram-stain-negative, rod-shaped, aerobic and non-motile bacterial strain designated K3R-10T was isolated from a freshwater source. The strain grew over a temperature range from 4 to 35 °C (optimum, 30 °C), pH range pH 6-8 (optimum, pH 7) and in the presence of 0-0.5 % NaCl (optimum, 0 %). Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain K3R-10T belonged to the genus Flavobacterium and shared close similarities with Flavobacterium succinicans LMG 10402T (97.0 %), Flavobacterium chungangense LMG 26729T (96.4 %), Flavobacterium branchiophilum IFO 15030T (96.4 %) and Flavobacteriumpiscis412R-09T (96.3 %), but formed a distinct phylogenetic line of its own in the phylogenetic trees. The polar lipids consisted of phosphatidylethanolamine, an unidentified aminolipid and three unidentified phospholipids. The DNA G+C content was 35.4 mol%, MK-6 was the major isoprenoid quinone, and homospermidine was the predominant polyamine. The predominant cellular fatty acids were iso-C15 : 0 3-OH, iso-C15 : 0, a summed feature comprising C16 : 1ω7c and/or C16 : 1ω6c and iso-C15 : 1 G. The absence of aminophospholipid, acid production from carbohydrates, DNA G+C content and colony morphology differentiated strain K3R-10T from related species of the genus Flavobacterium. Thus, on the basis of phenotypic, chemotaxonomic and phylogenetic features, strain K3R-10T evidently represents a novel species in the genus Flavobacterium, for which the name Flavobacterium keumense sp. nov. is proposed. The type strain is K3R-10T (=JCM 31220T=KCTC 52563T).
从淡水水源中分离出一株黄色色素沉着、氧化酶阳性、过氧化氢酶阴性、革兰氏染色阴性、杆状、需氧且不运动的细菌菌株，命名为K3R-10T。该菌株在4至35 °C（最适温度为30 °C）的温度范围内、pH值6至8（最适pH值为7）以及0至0.5 % NaCl（最适浓度为0 %）的条件下生长。基于16S rRNA基因序列的系统发育分析表明，菌株K3R-10T属于黄杆菌属，与琥珀黄杆菌LMG 10402T（相似度97.0 %）、忠南黄杆菌LMG 26729T（相似度96.4 %）、嗜鳃黄杆菌IFO 15030T（相似度96.4 %）和鱼黄杆菌412R-09T（相似度96.3 %）具有密切相似性，但在系统发育树中形成了一个独特的进化分支。极性脂质由磷脂酰乙醇胺、一种未鉴定的氨基脂质和三种未鉴定的磷脂组成。DNA的G+C含量为35.4 mol%，MK-6是主要的类异戊二烯醌，高亚精胺是主要的多胺。主要的细胞脂肪酸为异-C15 : 0 3-OH、异-C15 : 0、一个包含C16 : 1ω7c和/或C16 : 1ω6c的总和特征以及异-C15 : 1 G。氨基磷脂的缺失、碳水化合物产酸情况、DNA的G+C含量以及菌落形态使菌株K3R-10T与黄杆菌属的相关物种区分开来。因此，基于表型、化学分类和系统发育特征，菌株K3R-10T显然代表了黄杆菌属中的一个新物种，为此提出新名称黄杆菌（Flavobacterium keumense）。模式菌株为K3R-10T（=JCM 31220T=KCTC 52563T）。
