02110naa a2200193 a 450000100080000000500110000800800410001902400410006010000230010124501600012426000090028452014250029365300400171870000190175870000140177770000180179170000160180977300910182519329472017-08-05       2012    bl uuuu     u00u1 u    #d7 a10.1590/S1517-838220120002000352DOI1 aDELAMUTA, J. R. M.  aMultilocus sequence analysis (MLSA) of Bradyrhizobium strainsbrevealing high diversity of tropical diazotrophic symbiotic bacteria.h[electronic resource]  c2012  aSymbiotic association of several genera of bacteria collectively called as rhizobia and plants belonging to the family Leguminosae (=Fabaceae) results in the process of biological nitrogen fixation, playing a key role in global N cycling, and also bringing relevant contributions to the agriculture. Bradyrhizobium is considered as the ancestral of all nitrogen-fixing rhizobial species, probably originated in the tropics. The genus encompasses a variety of diverse bacteria, but the diversity captured in the analysis of the 16S rRNA is often low. In this study, we analyzed twelve Bradyrhizobium strains selected from previous studies performed by our group for showing high genetic diversity in relation to the described species. In addition to the 16S rRNA, five housekeeping genes (recA, atpD, glnII, gyrB and rpoB) were analyzed in the MLSA (multilocus sequence analysis) approach. Analysis of each gene and of the concatenated housekeeping genes captured a considerably higher level of genetic diversity, with indication of putative new species. The results highlight the high genetic variability associated with Bradyrhizobium microsymbionts of a variety of legumes. In addition, the MLSA approach has proved to represent a rapid and reliable method to be employed in phylogenetic and taxonomic studies, speeding the identification of the still poorly known diversity of nitrogen-fixing rhizobia in the tropics.  aFixação biológica de nitrogênio1 aRIBEIRO, R. A.1 aMENNA, P.1 aBANGEL, E. V.1 aHUNGRIA, M.  tBrazilian Journal of Microbiology, São Paulogv. 43, n.2, p. 698-710, Apr./June 2012.