Abstract：
Three bacterial strains, 1AS11T, 1AS12 and 1AS13, members of the new symbiovar salignae and isolated from root nodules of Acacia saligna grown in Tunisia, were characterized using a polyphasic approach. All three strains were assigned to the Rhizobium leguminosarum complex on the basis of rrs gene analysis. Phylogenetic analysis based on 1734 nucleotides of four concatenated housekeeping genes (recA, atpD, glnII and gyrB) showed that the three strains were distinct from known rhizobia species of the R. leguminosarum complex and clustered as a separate clade within this complex. Phylogenomic analysis of 92 up-to-date bacterial core genes confirmed the unique clade. The digital DNA-DNA hybridization and blast-based average nucleotide identity values for the three strains and phylogenetically related Rhizobium species ranged from 35.9 to 60.0% and 87.16 to 94.58 %, which were lower than the 70 and 96% species delineation thresholds, respectively. The G+C contents of the strains were 60.82-60.92 mol% and the major fatty acids (>4 %) were summed feature 8 (57.81 %; C18 : 1 ω7c) and C18 : 1 ω7c 11-methyl (13.24%). Strains 1AS11T, 1AS12 and 1AS13 could also be differentiated from their closest described species (Rhizobium indicum, Rhizobium laguerreae and Rhizobium changzhiense) by phenotypic and physiological properties as well as fatty acid content. Based on the phylogenetic, genomic, physiological, genotypic and chemotaxonomic data presented in this study, strains 1AS11T, 1AS12 and 1AS13 represent a new species within the genus Rhizobium and we propose the name Rhizobium acaciae sp. nov. The type strain is 1AS11T (=DSM 113913T=ACCC 62388T).
摘要：
三种细菌菌株，1AS11T,1AS12和1AS13，新的共生体salignae的成员，并从突尼斯生长的相思树的根瘤中分离出来，使用多相方法进行表征。根据rrs基因分析，将所有三个菌株都分配给豆科根瘤菌复合体。基于四个串联管家基因的1734个核苷酸的系统发育分析（recA，atpD,glnII和gyrB）表明，这三个菌株与豆科的已知根瘤菌不同。对92个最新细菌核心基因的系统基因组分析证实了独特的进化枝。三个菌株和系统发育相关的根瘤菌的数字DNA-DNA杂交和基于blast的平均核苷酸同一性值范围为35.9至60.0％和87.16至94.58％，低于70%和96%的物种划分阈值，分别。菌株的GC含量为60.82-60.92mol％，主要脂肪酸（>4％）的总和为特征8（57.81％；C18：1ω7c）和C18：1ω7c11-甲基（13.24％）。菌株1AS11T,1AS12和1AS13也可以与它们最接近的描述物种(印度根瘤菌，根瘤菌和根瘤菌）的表型和生理特性以及脂肪酸含量。基于系统发育，基因组，生理,这项研究中提供的基因型和化学分类学数据，菌株1AS11T，1AS12和1AS13代表根瘤菌属中的一个新物种，我们提出名称为根瘤菌。11月。菌株类型为1AS11T(=DSM113913T=ACCC62388T)。
