School of Integrative Plant Sciences, Bradfield Hall, Cornell University, Ithaca, NY, 14853, USA.
Lycoming College, Williamsport, PA, 17701, USA.
Int J Syst Evol Microbiol. 2020 Sep;70(9):5093-5105. doi: 10.1099/ijsem.0.004387.
Two bacterial strains, 1N and 5N, were isolated from hemlock forest soil using a soluble organic matter enrichment. Cells of 1N (0.65×1.85 µm) and 5N (0.6×1.85 µm) are Gram-stain-negative, aerobic, motile, non-sporulating and exist as single rods, diplobacilli or in chains of varying length. During growth in dilute media (≤0.1× tryptic soy broth; TSB), cells are primarily motile with flagella. At higher concentrations (≥0.3× TSB), cells of both strains increasingly form non-motile chains, and cells of 5N elongate (0.57×~7 µm) and form especially long filaments. Optimum growth of 1N and 5N occurred at 25-30 °C, pH 6.5-7.0 and <0.5% salinity. Results of comparative chemotaxonomic, genomic and phylogenetic analyses revealed that 1N and 5N were distinct from one another and their closest related type strains: RP11, LMG 27731 and CF1. The genomes of 1N and 5N had an average nucleotide identity (91.6 and 91.3%) and DNA-DNA hybridization values (45.8%±2.6 and 45.5%±2.5) and differed in functional gene content from their closest related type strains. The composition of fatty acids and patterns of substrate use, including the catabolism of phenolic acids, also differentiated strains 1N and 5N from each other and their closest relatives. The only ubiquinone present in strains 1N and 5N was Q-8. The major cellular fatty acids were C, 3OH-C, C cyclo, C cyclo ω8 and summed features 2 (3OH-C / C iso I), 3 (C ω6/ω7) and 8 (C ω7/ω6). A third bacterium, strain RL16-012-BIC-B, was isolated from soil associated with shallow roots and was determined to be a strain of (ANI, 98.8%; 16S rRNA gene similarity, 100%). Characterizations of strain RL16-012-BIC-B (DSM 110723=LMG 31706) led to proposed emendments to the species description of . Our polyphasic approach demonstrated that strains 1N and 5N represent novel species from the genus for which the names sp. nov. (type strain 1N=DSM 110721=LMG 31704) and sp. nov. (type strain 5N=DSM 110722=LMG 31705) are proposed.
从铁杉林土壤中使用可溶性有机质富集分离出两株细菌菌株 1N 和 5N。1N（0.65×1.85 µm）和 5N（0.6×1.85 µm）的细胞革兰氏阴性、需氧、运动、非孢子形成，呈单根、双杆菌或不同长度的链存在。在稀释培养基（≤0.1×胰蛋白酶大豆肉汤；TSB）中生长时，细胞主要通过鞭毛运动。在较高浓度（≥0.3×TSB）下，两种菌株的细胞越来越多地形成非运动链，而 5N 菌株的细胞伸长（0.57×~7 µm）并形成特别长的丝。1N 和 5N 的最佳生长温度为 25-30°C，pH 值为 6.5-7.0，盐度<0.5%。比较化学分类学、基因组学和系统发育分析的结果表明，1N 和 5N 彼此不同，与它们最接近的参考菌株：RP11、LMG 27731 和 CF1 也不同。1N 和 5N 的基因组平均核苷酸同一性（91.6 和 91.3%）和 DNA-DNA 杂交值（45.8%±2.6 和 45.5%±2.5）以及功能基因含量与它们最接近的参考菌株不同。脂肪酸组成和底物利用模式，包括酚酸的分解代谢，也将菌株 1N 和 5N 彼此区分开来，并将它们与最亲近的亲缘关系区分开来。菌株 1N 和 5N 中存在的唯一泛醌是 Q-8。主要细胞脂肪酸为 C、3OH-C、C 环、C 环 ω8 和总和特征 2（3OH-C/C iso I）、3（C ω6/ω7）和 8（C ω7/ω6）。第三种细菌菌株 RL16-012-BIC-B 从与浅层根系相关的土壤中分离出来，被确定为菌株 （ANI，98.8%；16S rRNA 基因相似度，100%）。对菌株 RL16-012-BIC-B（DSM 110723=LMG 31706）的特征描述导致对 属种描述的修正。我们的多相方法表明，菌株 1N 和 5N 代表了来自属的新型物种，建议将其命名为 sp. nov.（模式菌株 1N=DSM 110721=LMG 31704）和 sp. nov.（模式菌株 5N=DSM 110722=LMG 31705）。
