LSTM, Univ Montpellier, CIRAD, INRAE, IRD, Institut Agro Montpellier, Montpellier, France; Faculty of Agronomy II, Damascus University, and Faculty of Medicine, Syrian Private University, Damascus, Syria.
Laboratory of Microbiology, Dept. Biochemistry and Microbiology, Ghent University, Ghent, Belgium.
Syst Appl Microbiol. 2022 Sep;45(5):126341. doi: 10.1016/j.syapm.2022.126341. Epub 2022 Jun 16.
Ten mesorhizobial strains isolated from root-nodules of Anthyllis vulneraria by trapping using soils from southern France were studied to resolve their taxonomy. Their 16S rDNA sequences were identical and indicated that they are affiliated to the genus Mesorhizobium within the group M. prunaredense/M. delmotii/M. temperatum/M. mediterraneum/M. wenxiniae and M. robiniae as the closest defined species. Their evolutionary relationships with validated species were further characterized by multilocus sequence analysis (MLSA) using 4 protein-coding housekeeping genes (recA, atpD, glnII and dnaK), that divides the strains in two groups, and suggest that they belong to two distinct species. These results were well-supported by MALDI-TOF mass spectrometry analyses, wet-lab DNA-DNA hybridization (≤58%), and genome-based species delineation methods (ANI < 96%, in silico DDH < 70%), confirming their affiliation to two novel species. Based on these differences, Mesorhizobium ventifaucium (STM4922 = LMG 29643 = CFBP 8438) and Mesorhizobium escarrei (type strain STM5069 = LMG 29642 = CFBP 8439) are proposed as names for these two novel species. The phylogeny of nodulation genes nodC and nodA allocated the type strains into symbiovar anthyllidis as well as those of M. metallidurans STM2683, M. delmotii STM4623 and M. prunaredense STM4891, all recovered from the same legume species.
从法国南部土壤中通过诱捕法从脆弱黄花稔根瘤中分离的 10 株根瘤菌菌株，对其进行了研究以解决其分类学问题。它们的 16S rDNA 序列完全相同，表明它们属于中慢生根瘤菌/德氏根瘤菌/中温根瘤菌/地中海根瘤菌/温心根瘤菌/蔷薇根瘤菌组内的中慢生根瘤菌属，与最接近的已定义种 M. prunaredense 最为相近。通过使用 4 个蛋白编码看家基因（recA、atpD、glnII 和 dnaK）的多位点序列分析（MLSA）进一步对它们与验证种的进化关系进行了表征，该分析将菌株分为两组，并表明它们属于两个不同的种。这些结果通过 MALDI-TOF 质谱分析、湿实验室 DNA-DNA 杂交（≤58%）和基于基因组的物种划分方法（ANI<96%，in silico DDH<70%）得到了很好的支持，证实了它们与两个新种的关联。基于这些差异，中慢生根瘤菌 ventifaucium（STM4922=LMG 29643=CFBP 8438）和中慢生根瘤菌 escarrei（STM5069=type strain LMG 29642=CFBP 8439）被提议作为这两个新种的名称。nodC 和 nodA 基因的系统发育将这些模式菌株分配到 symbiovar anthyllidis 中，以及从同一豆科植物中分离到的 M. metallidurans STM2683、M. delmotii STM4623 和 M. prunaredense STM4891 的模式菌株。
