Celador-Lera Lorena, Menéndez Esther, Peix Alvaro, Igual José M, Velázquez Encarna, Rivas Raúl
Departamento de Microbiología y Genética and Instituto Hispanoluso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Salamanca, Spain.
Instituto de Recursos Naturales y Agrobiología de Salamanca, Consejo Superior de Investigaciones Científicas, (IRNASA-CSIC), Salamanca, Spain.
Int J Syst Evol Microbiol. 2017 Jul;67(7):2306-2311. doi: 10.1099/ijsem.0.001944. Epub 2017 Jul 12.
A bacterial strain designated CRZM18RT was isolated from a root of Zea mays in Spain. The analysis of the 16S rRNA gene sequence showed that this strain belongs to the genus Rhizobium, with Rhizobium cellulosilyticum ALA10B2T and Rhizobium yantingense H66T being the most closely related species with 98.3 and 97.9 % sequence similarity, respectively. The analysis of the concatenated recA and atpD genes showed that strain CRZM18RT forms a cluster with these species and also with Rhizobiumsmilacinae PTYR-5T, but the recA and atpD genes of strain CRZM18RT were phylogenetically distant, with identities lower than 90 and 96 %, respectively. DNA-DNA hybridization analysis showed mean relatedness of 43, 22 and 38 % with respect to R. cellulosilyticum ALA10B2T, R. yantingense LMG 28229T and R. smilacinae LMG 27604T. Phenotypic characteristics also differed from those of the most closely related species of the genus Rhizobium. The major fatty acids were those from summed feature 8 (C18 : 1ω6c/C18 : 1ω7c) and C16 : 0. Based on the genotypic, chemotaxonomic and phenotypic data obtained in this study, we propose to classify strain CRZM18RT in a novel species named Rhizobium zeae sp. nov. (type strain CRZM18RT=LMG 29735T=CECT 9169T).
一株命名为CRZM18RT的细菌菌株是从西班牙的玉米根部分离得到的。16S rRNA基因序列分析表明，该菌株属于根瘤菌属，与纤维素分解根瘤菌ALA10B2T和盐亭根瘤菌H66T最为接近，序列相似性分别为98.3%和97.9%。recA和atpD串联基因分析表明，CRZM18RT菌株与这些物种以及菝葜根瘤菌PTYR-5T形成一个聚类，但CRZM18RT菌株的recA和atpD基因在系统发育上较远，同一性分别低于90%和96%。DNA-DNA杂交分析表明，与纤维素分解根瘤菌ALA10B2T、盐亭根瘤菌LMG 28229T和菝葜根瘤菌LMG 27604T的平均相关性分别为43%、22%和38%。表型特征也与根瘤菌属关系最密切的物种不同。主要脂肪酸为总和特征8（C18:1ω6c/C18:1ω7c）和C16:0中的脂肪酸。根据本研究获得的基因型、化学分类和表型数据，我们建议将CRZM18RT菌株分类为一个新物种，命名为玉米根瘤菌（Rhizobium zeae sp. nov.）（模式菌株CRZM18RT = LMG 29735T = CECT 9169T）。
