Cai Yimin, Yang Jinsong, Pang Huili, Kitahara Maki
Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan.
Hainan University, Haikou, Hainan 570228, PR China.
Int J Syst Evol Microbiol. 2011 Jul;61(Pt 7):1590-1594. doi: 10.1099/ijs.0.025130-0. Epub 2010 Jul 30.
Three strains of lactic acid bacteria, designated NJ 317(T), NJ 414 and NJ 415, were isolated from the outer leaves of Chinese cabbages (Brassica rapa L. var. glabra Regel) and characterized taxonomically. The strains were gram-reaction-positive, catalase-negative, facultatively anaerobic cocci that did not produce gas from glucose and formed L-lactic acid. The major fatty acids were C(18 : 1)ω9c, C(16 : 0), C(14 : 0) and summed feature 10. Morphological, physiological and phylogenetic data indicated that the strains belonged to the genus Lactococcus. These strains shared similar phenotypic characteristics and exhibited DNA relatedness values >96.6 % to each other, indicating that they represent a single species. The DNA G+C contents of the three strains were 42.1-42.5 mol%. 16S rRNA gene sequences of the novel strains were determined and aligned with those of other species of the genus Lactococcus. On the basis of phylogenetic analysis the three strains grouped with other members of the genus Lactococcus. Lactococcus lactis and Lactococcus garvieae were the most closely related species, sharing a sequence similarity value of 94.4 % with the three strains. Ribotyping patterns, however, revealed that these strains were well-separated from reference strains of species of the genus Lactococcus and DNA-DNA hybridization studies indicated that the novel strains had low levels (<20.2 %) of DNA relatedness with reference strains of L. lactis, L. garvieae and other type strains of previously described species, showing that they represent a different species. Based on this evidence, strains NJ 317(T), NJ 414 and NJ 415 represent a novel species of the genus Lactococcus, for which the name Lactococcus fujiensis sp. nov. is proposed. The type strain is NJ 317(T) ( = JCM16395(T) = CGMCC 1.10453(T)).
从大白菜（Brassica rapa L. var. glabra Regel）外叶中分离出三株乳酸菌，分别命名为NJ 317(T)、NJ 414和NJ 415，并进行了分类学特征分析。这些菌株革兰氏反应阳性、过氧化氢酶阴性，为兼性厌氧球菌，不利用葡萄糖产气，可产生L-乳酸。主要脂肪酸为C(18 : 1)ω9c、C(16 : 0)、C(14 : 0)和总和特征10。形态学、生理学和系统发育数据表明这些菌株属于乳球菌属。这些菌株具有相似的表型特征，相互之间的DNA相关性值>96.6 %，表明它们代表一个单一物种。这三株菌株的DNA G+C含量为42.1-42.5 mol%。测定了这些新菌株的16S rRNA基因序列，并与乳球菌属其他物种的序列进行比对。基于系统发育分析，这三株菌株与乳球菌属的其他成员聚类。乳酸乳球菌和格氏乳球菌是关系最密切的物种，与这三株菌株的序列相似性值为94.4 %。然而，核糖体分型图谱显示这些菌株与乳球菌属物种的参考菌株有明显区别，DNA-DNA杂交研究表明新菌株与乳酸乳球菌、格氏乳球菌及其他先前描述物种的模式菌株的DNA相关性较低（<20.2 %），表明它们代表一个不同的物种。基于这些证据，菌株NJ 317(T)、NJ 414和NJ 415代表乳球菌属的一个新物种，为此提出新名称富士山乳球菌（Lactococcus fujiensis sp. nov.）。模式菌株为NJ 317(T)（=JCM16395(T)=CGMCC 1.10453(T)）。
