Multilocus sequence analysis of Bosea species and description of Bosea lupini sp. nov., Bosea lathyri sp. nov. and Bosea robiniae sp. nov., isolated from legumes

Abstract

Gram-negative, rod-shaped bacteria were isolated from root nodules of Lupinus polyphyllus, Lathyrus latifolius and Robinia pseudoacacia. Based on the 16S rRNA gene phylogeny, they were closely related to Bosea species (100–97 % similarity), belonging to the class Alphaproteobacteria , family Bradyrhizobiaceae . The closest relatives of LMG 26383T, LMG 26379T and LMG 26381T were respectively the type strains of Bosea thiooxidans (99.6 %), B. eneae (98.3 %) and B. minatitlanensis (99.0 %). Chemotaxonomic data, including major fatty acid profiles, supported the assignment of our strains to the genus Bosea . Analysis of the concatenated sequences of five housekeeping genes (atpD, dnaK, gyrB, recA and rpoB) and the results of DNA–DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of our strains from each other and from the five Bosea species with validly published names. No nodA or nodC genes could be amplified, while nifH PCR gave non-specific products. On the basis of genotypic and phenotypic data, three novel species, Bosea lupini sp. nov. (type strain LMG 26383T  = CCUG 61248T  = R-45681T), Bosea lathyri sp. nov. (type strain LMG 26379T  = CCUG 61247T  = R-46060T) and Bosea robiniae sp. nov. (type strain LMG 26381T  = CCUG 61249T  = R-46070T), are proposed.