This study describes two Bradyrhizobium strains, UFLA03-164T and UFLA03-153, which share more than 99% sequence similarity of the 16S rRNA with the type strains of 15 species in this genus. The concatenation of three housekeeping genes (recA, gyrB, and dnaK) indicated that both strains formed a single clade separate from known Bradyrhizobium species. B. viridifuturi, represented by SEMIA 690T, is the closest neighboring species (96.2%). Low (< 92%) average nucleotide identity (ANI) was observed between strain UFLA03-164T and any of the closest species on the phylogenetic trees based on concatenated housekeeping genes. The DNA G+C content of UFLA03-164T is 63.25%. Phenotypic characteristics were determined for both UFLA strains. Based on the data, the two strains represent a new species for which the name Bradyrhizobium uaiense is proposed, with UFLA03-164T (= LMG 31509T) as type strain.
Keywords: Biological nitrogen fixation; Bradyrhizobium; Phylogeny; Plant growth-promoting bacteria; Taxonomy.