Brazilian Journal of Microbiology Brazilian Journal of Microbiology
Braz J Microbiol 2018;49:703-13 - Vol. 49 Num.4 DOI: 10.1016/j.bjm.2017.01.007
Environmental Microbiology
Genomic identification and characterization of the elite strains Bradyrhizobium yuanmingense BR 3267 and Bradyrhizobium pachyrhizi BR 3262 recommended for cowpea inoculation in Brazil
Jakson Leitea, Samuel Ribeiro Passosb, Jean Luiz Simões-Araújoc, Norma Gouvêa Rumjanekd, Gustavo Ribeiro Xavierd, Jerri Édson Zillid,,
a Departamento de Solos, Universidade Federal Rural do Rio de Janeiro, 23851-970 Seropédica, RJ, Brazil
b Departamento de Ciências Ambientais, Universidade Federal Rural do Rio de Janeiro, 23851-970 Seropédica, RJ, Brazil
c Laboratório de Genética e Bioquímica, Embrapa Agrobiologia, 23851-970 Seropédica, RJ, Brazil
d Laboratório de Ecologia Microbiana, Embrapa Agrobiologia, 23851-970 Seropédica, RJ, Brazil
Received 03 October 2016, Accepted 12 January 2017
Abstract

The leguminous inoculation with nodule-inducing bacteria that perform biological nitrogen fixation is a good example of an “eco-friendly agricultural practice”. Bradyrhizobium strains BR 3267 and BR 3262 are recommended for cowpea (Vigna unguiculata) inoculation in Brazil and showed remarkable responses; nevertheless neither strain was characterized at species level, which is our goal in the present work using a polyphasic approach. The strains presented the typical phenotype of Bradyrhizobium with a slow growth and a white colony on yeast extract-mannitol medium. Strain BR 3267 was more versatile in its use of carbon sources compared to BR 3262. The fatty acid composition of BR 3267 was similar to the type strain of Bradyrhizobium yuanmingense; while BR 3262 was similar to Bradyrhizobium elkanii and Bradyrhizobium pachyrhizi. Phylogenetic analyses based on 16S rRNA and three housekeeping genes placed both strains within the genus Bradyrhizobium: strain BR 3267 was closest to B. yuanmingense and BR 3262 to B. pachyrhizi. Genome average nucleotide identity and DNA–DNA reassociation confirmed the genomic identification of B. yuanmingense BR 3267 and B. pachyrhizi BR 3262. The nodC and nifH gene analyses showed that strains BR 3267 and BR 3262 hold divergent symbiotic genes. In summary, the results indicate that cowpea can establish effective symbiosis with divergent bradyrhizobia isolated from Brazilian soils.

Keywords
Vigna unguiculata, Rhizobia, MLSA, DDH, ANI
Braz J Microbiol 2018;49:703-13 - Vol. 49 Num.4 DOI: 10.1016/j.bjm.2017.01.007
Cookies Policy
x
To improve our services and products, we use cookies (own or third parties authorized) to show advertising related to client preferences through the analyses of navigation customer behavior. Continuing navigation will be considered as acceptance of this use. You can change the settings or obtain more information by clicking here.