Dall' Agnol R. F. auteur aut IRD Bournaud C. auteur aut IRD de Faria S. M. auteur aut IRD Béna Gilles auteur aut IRD Moulin Lionel auteur aut IRD Hungria M. auteur aut IRD text journalArticle eng text/pdf born digital access Some species of the genus Paraburkholderia that are able to nodulate and fix nitrogen in symbiosis with legumes are called beta-rhizobia and represent a group of ecological and biotechnological importance. We used Mimosa pudica and Phaseolus vulgaris to trap 427 rhizobial isolates from rhizospheric soil of Mimoseae trees in the Brazilian Atlantic Forest. Eighty-four representative strains were selected according to the 16S rRNA haplotypes and taxonomically characterized using a concatenated 16S rRNA-recA phylogeny. Most strains were assembled in the genus Paraburkholderia, including Paraburkholderia sabiae and Pa. nodosa. Mesorhizobium (alpha-rhizobia) and Cupriavidus (beta-rhizobia) were also isolated, but in smaller proportions. Multilocus sequence analysis and BOX-PCR analyses indicated that six clusters of Paraburkholderia represent potential new species. In the phylogenetic analysis of the nodC gene, the majority of the strains were positioned in the same groups as in the 16S rRNA-recA tree, indicative of stability and vertical inheritance, but we also identified horizontal transfer of nodC in Pa. sabiae. All alpha- and beta-rhizobial species were trapped by both legumes, although preferences of the host plants for specific rhizobial species have been observed. specialized biological nitrogen fixation diazotrophic bacteria beta-rhizobia phylogeny nodulation BRESIL 084 93 4 fix027 [15 p.] 2017 0168-6496 https://www.documentation.ird.fr/hor/fdi:010070311 10.1093/femsec/fix027 0168-6496 [F B010070311] https://www.documentation.ird.fr/hor/fdi:010070311 https://www.documentation.ird.fr/intranet/publi/2017/08/010070311.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2017-09-05 2018-01-02 fdi:010070311 fre