Tohno Masanori, Tanizawa Yasuhiro, Irisawa Tomohiro, Masuda Takaharu, Sakamoto Mitsuo, Arita Masanori, Ohkuma Moriya, Kobayashi Hisami
Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Nasushiobara, Tochigi, 329-2793, Japan.
Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.
Int J Syst Evol Microbiol. 2017 Sep;67(9):3639-3644. doi: 10.1099/ijsem.0.002196. Epub 2017 Sep 7.
Three Gram-stain positive, non-motile, non-spore-forming, catalase-negative and rod-shaped bacterial strains (IWT5T, IWT25T and IWT140), isolated from silage, were investigated by using a polyphasic taxonomic approach. Strains IWT5T and IWT25T grew at 10-37 °C and 30-37 °C, and at pH 4.0-7.5 and 4.0-7.0, respectively. The G+C contents of genomic DNA of strains IWT5T and IWT25T were 43.2 and 44.4 mol%, respectively. Strains IWT5T and IWT25T contained C16 : 0, C18 : 1 ω9c and summed feature 7 (unknown 18.846/C19 : 1 ω6c/C19 : 0cyclo ω10c) as the major fatty acids. Strain IWT5T was most closely related to the type strains of Lactobacillus mixtipabuli (99.9 % 16S rRNA gene sequence similarity) and Lactobacillus silagei (99.5 %). For IWT25T, the 16S rRNA gene sequence similarities with the closely related neighbour type strains L. mixtipabuli and L. silagei were 99.5 and 99.5 %, respectively. The 16S rRNA gene sequence similarities among the three novel isolates were 99.5-99.9 %. The average nucleotide identities of strains IWT5T and IWT25T to other neighbours of the genus Lactobacillus were less than 82 % and the genomes of IWT25T and IWT140 shared 97.3 % average nucleotide identity, demonstrating that the three strains were allocated to two different novel species of the genus Lactobacillus. Together with multilocus sequence analysis, phenotypic and chemotaxonomic characteristics, strains IWT5T (=JCM 31144T=DSM 102973T) and IWT25T (=JCM 31145T=DSM 102974T) are proposed as the type strains of novel species of the genus Lactobacillus, with the names Lactobacillus silagincola sp. nov. and Lactobacillus pentosiphilus sp. nov., respectively.
从青贮饲料中分离出三株革兰氏染色阳性、无运动性、不形成芽孢、过氧化氢酶阴性的杆状细菌菌株（IWT5T、IWT25T和IWT140），采用多相分类法对其进行了研究。菌株IWT5T和IWT25T分别在10 - 37 °C和30 - 37 °C生长，在pH 4.0 - 7.5和4.0 - 7.0生长。菌株IWT5T和IWT25T基因组DNA的G+C含量分别为43.2和44.4 mol%。菌株IWT5T和IWT25T含有C16 : 0、C18 : 1 ω9c和总和特征7（未知18.846/C19 : 1 ω6c/C19 : 0环ω10c）作为主要脂肪酸。菌株IWT5T与混合乳杆菌（Lactobacillus mixtipabuli）模式菌株（16S rRNA基因序列相似性为99.9 %）和青贮乳杆菌（Lactobacillus silagei）（99.5 %）关系最为密切。对于IWT25T，与密切相关的近邻模式菌株混合乳杆菌和青贮乳杆菌的16S rRNA基因序列相似性分别为99.5和99.5 %。三株新分离菌株之间的16S rRNA基因序列相似性为99.5 - 99.9 %。菌株IWT5T和IWT25T与乳杆菌属其他近缘菌株的平均核苷酸同一性小于82 %，IWT25T和IWT140的基因组平均核苷酸同一性为97.3 %，表明这三株菌株被归为乳杆菌属的两个不同新物种。结合多位点序列分析、表型和化学分类特征，菌株IWT5T（=JCM 31144T=DSM 102973T）和IWT25T（=JCM 31145T=DSM 102974T）被提议作为乳杆菌属新物种的模式菌株，分别命名为青贮乳杆菌（Lactobacillus silagincola sp. nov.）和戊糖乳杆菌（Lactobacillus pentosiphilus sp. nov.）。
