Mesorhizobium robiniae sp. nov., isolated from root nodules of Robinia pseudoacacia.

Previously, five rhizobial strains isolated from root nodules of Robinia pseudoacacia were assigned to the same genospecies on the basis of identical 16S rRNA gene sequences and phylogenetic analyses of the nodA, nodC and nifH genes, in which the five isolates formed a well-supported group that excluded other sequences found in public databases. In this study, the 16S rRNA gene sequence similarities between the isolates and Mesorhizobium mediterraneum UPM-Ca36(T) and Mesorhizobium temperatum SDW018(T) were 99.5 and 99.