University of Chinese Academy of Sciences, Beijing 100049, PR China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
Int J Syst Evol Microbiol. 2020 Mar;70(3):2124-2131. doi: 10.1099/ijsem.0.004026.
Three aerobic, asymbiotic, N-fixing bacterial strains, designated P205, P204 and P207, were isolated from a paddy soil in Yanting County, China. Based on 16S rRNA gene sequences, the three strains were closely related to IAM 12666 (=ATCC 9043) (99.00-99.79 % similarities). Strain P205 formed an individual branch distinct from the other two newly isolated strains and other related type strains in phylogenetic analyses based on 16S rRNA gene and 92 core genes. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values based on genome sequences of strain P205 and ATCC 9043, P204, P207 were near or slightly higher than the thresholds for species circumscription (95-96, 95-96 and 70 %, respectively), and the dDDH values were significantly lower than the threshold for delineating subspecies (79-80 %), which strongly supported that strain P205 belonged to but was a novel subspecies distinct from the type strain of . This finding was further corroborated by distinct phenotypic characteristics such as growth in Luria-Bertani (LB) medium, carbon source utilization and chemical sensitivity to vancomycin. Therefore, strain P205 represents a novel subspecies of , for which the name subsp. subsp. nov. is proposed with the type strain P205 (=KCTC 72233=CGMCC 1.16846=CCTCC AB 2019080). The subspecies subsp. subsp. nov. is created automatically with the type strain ATCC 9043 (=DSM 2286=JCM 20725=JCM 21503=LMG 8756=NBRC 102613=NCAIM B.01391=NRRL B-14346=VKM B-1616).
三株好氧、共生、固氮细菌菌株,分别命名为 P205、P204 和 P207,从中国盐亭县稻田土壤中分离得到。基于 16S rRNA 基因序列,这三株菌与 IAM 12666(=ATCC 9043)(99.00-99.79%相似度)密切相关。菌株 P205 在基于 16S rRNA 基因和 92 个核心基因的系统发育分析中与其他两株新分离的菌株和其他相关的模式菌株形成一个独特的分支。基于基因组序列的菌株 P205 与 ATCC 9043、P204、P207 的平均核苷酸同一性(ANI)、平均氨基酸同一性(AAI)和数字 DNA-DNA 杂交(dDDH)值接近或略高于种的界定阈值(分别为 95-96%、95-96%和 70%),而 dDDH 值明显低于亚种界定阈值(79-80%),这强烈支持菌株 P205 属于但与模式菌株不同的一个新亚种。这一发现进一步得到了明显的表型特征的证实,如在 LB 培养基中的生长、碳源利用和对万古霉素的化学敏感性。因此,菌株 P205 代表 的一个新亚种,建议命名为 subsp. subsp. nov.,其模式菌株为 P205(=KCTC 72233=CGMCC 1.16846=CCTCC AB 2019080)。亚种 subsp. subsp. nov. 是与模式菌株 ATCC 9043(=DSM 2286=JCM 20725=JCM 21503=LMG 8756=NBRC 102613=NCAIM B.01391=NRRL B-14346=VKM B-1616)一起自动创建的。