Laboratory of Tropical Crop Science, Department of International Agricultural Development, Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Tokyo, Japan.
Laboratory of Bioinformatics, Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, Tokyo, Japan.
Int J Syst Evol Microbiol. 2020 Sep;70(9):5054-5062. doi: 10.1099/ijsem.0.004381. Epub 2020 Aug 17.
This study investigated endophytic nitrogen-fixing bacteria isolated from two species of yam (water yam, L.; lesser yam, L.) grown in nutrient-poor alkaline soil conditions on Miyako Island, Okinawa, Japan. Two bacterial strains of the genus , S-93 and S-62, were isolated. The phylogenetic tree, based on the almost-complete 16S rRNA gene sequences (1476 bp for each strain), placed them in a distinct clade, with CCBAU 41251, I66, HAMBI 2975, PRF 81 and CIAT 899 being their closest species. Their bacterial fatty acid profile, with major components of C cyclo 8 and summed feature 8, as well as other phenotypic characteristics and DNA G+C content (59.65 mol%) indicated that the novel strains belong to the genus . Pairwise average nucleotide identity analyses separated the novel strains from their most closely related species with similarity values of 90.5, 88.9, 88.5, 84.5 and 84.4 % for HAMBI 2975, CIAT 899, CCBAU 57015, HAMBI 2971 and PRF 81, respectively; digital DNA-DNA hybridization values were in the range of 26-42 %. Considering the phenotypic characteristics as well as the genomic data, it is suggested that strains S-93 and S-62 represent a new species, for which the name is proposed. The type strain is S-93 (=NRIC 0988=NBRC 114257=DSM 110498).
本研究调查了从日本冲绳宫古岛贫营养碱性土壤中生长的两种山药（水薯，L.；小薯，L.）中分离出的内生固氮细菌。从属 中分离出两种细菌菌株，S-93 和 S-62。基于几乎完整的 16S rRNA 基因序列（每个菌株 1476 bp）的系统发育树将它们置于一个独特的分支中，与 CCBAU 41251、I66、HAMBI 2975、PRF 81 和 CIAT 899 是它们最接近的物种。它们的细菌脂肪酸图谱，主要成分是 C 环 8 和总和特征 8，以及其他表型特征和 DNA G+C 含量（59.65 mol%）表明，新型菌株属于属 。新型菌株与最密切相关的物种之间的成对平均核苷酸同一性分析，其相似性值分别为 90.5、88.9、88.5、84.5 和 84.4%，与 HAMBI 2975、CIAT 899、CCBAU 57015、HAMBI 2971 和 PRF 81；数字 DNA-DNA 杂交值在 26-42%之间。考虑到表型特征和基因组数据，建议菌株 S-93 和 S-62 代表一个新物种，建议使用 来命名。模式菌株为 S-93（=NRIC 0988=NBRC 114257=DSM 110498）。
