Bradyrhizobium cajani sp. nov. isolated from nodules of Cajanus cajan.

Two slow-growing strains, AMBPC1010T and AMBPC1011, were isolated from nodules of Cajanus cajan in the Dominican Republic. 16S rRNA gene analysis placed these strains within the genus Bradyrhizobium, being phylogenetically equidistant to several species of this genus. Analysis of the recA and atpD genes showed that the strains isolated belong to a cluster containing the strains Bradyrhizobium ottawaense OO99T, 'Bradyrhizobium americanum' CMVU44 and Bradyrhizobium daqingense CCBAU 15774T, and presented similarity values lower than 96 % for both genes with respect to the strains nodulating C. cajan. DNA-DNA hybridization analysis showed averages of 36, 40 and 39 % relatedness with respect to the representative strains of Bradyrhizobium ottawaense, 'Bradyrhizobium americanum' and Bradyrhizobium daqingense, respectively. Phenotypic characteristics also differed from those of the most closely related species of the genus Bradyrhizobium. Therefore, based on the data obtained in this study, we propose to classify the strains AMBPC1010T (=LMG 29967T=CECT 9227T) and AMBPC1011 into a novel species named Bradyrhizobium cajani sp. nov.