Tanizawa Yasuhiro, Tada Ipputa, Kobayashi Hisami, Endo Akihito, Maeno Shintaro, Toyoda Atsushi, Arita Masanori, Nakamura Yasukazu, Sakamoto Mitsuo, Ohkuma Moriya, Tohno Masanori
1Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.
2Department of Genetics, School of Life Science, The Graduate University of Advanced Studies, Mishima, Shizuoka 411-8540, Japan.
Int J Syst Evol Microbiol. 2018 Nov;68(11):3512-3517. doi: 10.1099/ijsem.0.003020. Epub 2018 Sep 18.
Three strains, JCM 5343, JCM 5344 and JCM 1130, currently identified as Lactobacillus gasseri, were investigated using a polyphasic taxonomic approach. Although these strains shared high 16S rRNA gene sequence similarities with L. gasseri ATCC 33323 (99.9 %), they formed a clade clearly distinct from ATCC 33323 based on whole-genome relatedness. The average nucleotide identity and in silico DNA-DNA hybridization values of these three strains compared to L. gasseri ATCC 33323 were 93.4-93.7 and 53.1-54.1 %, respectively, and both were less than the widely accepted threshold to distinguish two species (95 and 70 %, respectively). The three strains were Gram-stain positive, non-motile, non-spore-forming, catalase-negative and rod-shaped bacteria. They grew at 25-45 °C and in the presence of 2.0 % (w/v) NaCl. The major fatty acids of the three strains were C16 : 0 and C18 : 1 ω9c. Based on phylogenetic analyses of the phenylalanyl-tRNA synthase alpha subunit and RNA polymerase alpha subunit genes, and on phenotypic and chemotaxonomic characteristics, strains JCM 5343, JCM 5344 and JCM 1130 represent a novel species distinct from L. gasseri, for which we propose the name Lactobacillusparagasseri sp. nov. In addition, a large portion of genomes currently labelled as L. gasseri in the public sequence database should be reclassified as L. paragasseri based on whole-genome relatedness.
采用多相分类学方法对目前鉴定为加氏乳杆菌的3株菌株JCM 5343、JCM 5344和JCM 1130进行了研究。尽管这些菌株与加氏乳杆菌ATCC 33323的16S rRNA基因序列相似度很高（99.9%），但基于全基因组相关性，它们形成了一个明显不同于ATCC 33323的进化枝。这三株菌株与加氏乳杆菌ATCC 33323相比，平均核苷酸同一性和电子DNA-DNA杂交值分别为93.4 - 93.7%和53.1 - 54.1%，均低于区分两个物种的广泛接受阈值（分别为95%和70%）。这三株菌株为革兰氏染色阳性、无运动性、不产芽孢、过氧化氢酶阴性的杆状细菌。它们在25 - 45℃以及2.0%（w/v）NaCl存在的条件下生长。这三株菌株的主要脂肪酸为C16:0和C18:1 ω9c。基于苯丙氨酰-tRNA合成酶α亚基和RNA聚合酶α亚基基因的系统发育分析，以及表型和化学分类学特征，菌株JCM 5343、JCM 5344和JCM 1130代表了一个不同于加氏乳杆菌的新物种，我们将其命名为副加氏乳杆菌（Lactobacillusparagasseri sp. nov.）。此外，基于全基因组相关性，公共序列数据库中目前标记为加氏乳杆菌的大部分基因组应重新分类为副加氏乳杆菌。
