A polyphasic study was performed to determine the taxonomic position of strain EK05T isolated from a root-outgrowth of Entada koshunensis, a legume available in Okinawa, Japan. Phylogenetic analysis of the 16S rRNA gene showed that the strain belongs to the genus Bradyrhizobium. Subsequent multilocus sequence analysis with ITS, glnII, recA, gyrB, and atpD sequences revealed that the isolate represents a distinct evolutionary lineage within the genus Bradyrhizobium. DNA-DNA hybridization indicated that strain EK05T shares <61% DNA relatedness with the type strains of all six recognized species of Bradyrhizobium, confirming that this strain is a novel species within the genus. Phylogenetic trees based on symbiotic loci, nifH and nodC, also placed strain EK05T clearly in a novel branch. On the basis of its phylogenetic distinctiveness, we propose Bradyrhizobium iriomotense sp. nov. for strain EK05T. The type strain is EK05T (= NBRC 102520T = LMG 24129T).
2008 by Japan Society for Bioscience, Biotechnology, and Agrochemistry