Institute of Arid Lands, Laboratory of Pastoral Ecosystems and Promotion of Spontaneous Plants and Associated Micro-Organisms, University of Gabes, Gabes, Tunisia.
Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, 38124 Braunschweig, Germany.
Int J Syst Evol Microbiol. 2024 Jul;74(7). doi: 10.1099/ijsem.0.006478.
A comprehensive polyphasic taxonomic investigation integrating taxongenomic criteria was conducted on strain IRAMC:0171 isolated from the root nodules of in Tunisia. This Gram-stain-negative and aerobic bacterium thrived within a temperature range of 5-45 °C, optimal at 28 °C, and tolerated salt concentrations from 0-6 % NaCl, with an optimal range of 0-3 %. It displayed pH tolerance from pH 4 to 10, thriving best at pH 6.8-7.5. Chemotaxonomically, strain IRAMC:0171 was characterized by diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, and phosphatidylethanolamine as polar lipids. Its predominant fatty acid composition was C 7c (61.2 %), and the primary ubiquinone was Q10 (97 %). Analysis of the 16S rRNA gene of strain IRAMC:0171 showed 99.08 % similarity to ICMP 19557, ACCC 19665, and IAM 14158. However, digital DNA-DNA hybridization and average nucleotide identity analyses revealed values ranging from 21.1 to 25.2 % and 77.05 to 82.24 %, respectively, signifying significant deviation from established species demarcation thresholds. Phylogenetic studies, encompassing 16S rRNA, whole-genome-based tree reconstruction, and core protein analysis, positioned strain IRAMC:0171 closest to KCTC 72278 and '' UASWS1009, forming together a distinct branch within the genus . In consideration of this comprehensive data, we propose strain IRAMC:0171 (=DSM 112841=CECT 30767) as the type strain of a new species named sp. nov.
对从突尼斯根瘤中分离得到的菌株 IRAMC:0171 进行了综合多相分类学研究，整合了分类基因组标准。该革兰氏阴性需氧菌在 5-45°C 的温度范围内生长良好，最佳温度为 28°C，可耐受 0-6%NaCl 的盐浓度，最佳范围为 0-3%。它在 pH 4 到 10 的范围内耐受 pH 值，在 pH 6.8-7.5 时生长最好。化学分类学上，菌株 IRAMC:0171 的特征为二磷脂酰甘油、磷脂酰甘油、磷脂酰胆碱和磷脂酰乙醇胺为极性脂。其主要脂肪酸成分为 C 7c（61.2%），主要的醌类为 Q10（97%）。对菌株 IRAMC:0171 的 16S rRNA 基因分析表明，与 ICMP 19557、ACCC 19665 和 IAM 14158 的相似度为 99.08%。然而，数字 DNA-DNA 杂交和平均核苷酸同一性分析显示，数值范围分别为 21.1%至 25.2%和 77.05%至 82.24%，表明与已建立的种分离标准存在显著偏差。系统发育研究，包括 16S rRNA、全基因组树重建和核心蛋白分析，将菌株 IRAMC:0171 定位与 KCTC 72278 和“UASWS1009”最为接近，在属内形成一个独特的分支。考虑到这些综合数据，我们建议将菌株 IRAMC:0171（=DSM 112841=CECT 30767）作为一个新种的模式菌株，命名为 sp. nov.
