RT Journal Article SR Electronic(1) A1 Dall’Agnol, Rebeca Fuzinatto A1 Ribeiro, Renan Augusto A1 Ormeño-Orrillo, Ernesto A1 Rogel, Marco Antonio A1 Delamuta, Jakeline Renata Marçon A1 Andrade, Diva Souza A1 Martínez-Romero, Esperanza A1 Hungria, MariangelaYR 2013 T1 Rhizobiumfreirei sp. nov., a symbiont of Phaseolus vulgaris that is very effective at fixing nitrogen JF International Journal of Systematic and Evolutionary Microbiology, VO 63 IS Pt_11 SP 4167 OP 4173 DO https://doi.org/10.1099/ijs.0.052928-0 PB Microbiology Society, SN 1466-5034, AB Common bean (Phaseolus vulgaris L.) can establish symbiotic associations with several Rhizobium species; however, the effectiveness of most strains at fixing nitrogen under field conditions is very low. PRF 81T is a very effective strain, usually referred to as Rhizobium tropici and used successfully in thousands of doses of commercial inoculants for the common bean crop in Brazil; it has shown high rates of nitrogen fixation in all areas representative of the crop in the country. Here, we present results that indicate that PRF 81T, although it belongs to the ‘ R. tropici group’, which includes 10 Rhizobium species, R. tropici , R. leucaenae , R. lusitanum , R. multihospitium , R. miluonense , R. hainanense , R. calliandrae , R. mayense , R. jaguaris and R. rhizogenes , represents a novel species. Several morpho-physiological traits differentiated PRF 81T from related species. Differences were also confirmed in the analysis of rep-PCR (sharing less than 45 % similarity with the other species), MLSA with recA, atpD and rpoB genes, and DNA–DNA hybridization. The novel species, for which we propose the name Rhizobium freirei sp. nov., is able to establish effective root nodule symbioses with Phaseolus vulgaris, Leucaena leucocephala, Leucaena esculenta, Crotalaria juncea and Macroptilium atropurpureum. The type strain is PRF 81T ( = CNPSo 122T = SEMIA 4080T = IPR-Pv81T = WDCM 440T)., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.052928-0