The York Research Database

Rhizobial strains isolated from effective root nodules of field-grown lentil (Lens culinaris) from different parts of Bangladesh were previously analyzed using four housekeeping genes (16S rRNA, recA, atpD and glnII) and three nodulation genes (nodA, nodC and nodD), DNA fingerprinting and phenotypic characterization. Analysis of housekeeping genes and DNA fingerprint indicated that the strains belonged to three new clades in the genus Rhizobium. In present study, a representative strain from each clade was further characterized by cellular fatty acid compositions, carbon substrate utilization pattern, DNA-DNA hybridization and average nucleotide identity (ANI) analyses from whole genome sequences. The DNA-DNA hybridization showed 50 - 56 % relatedness to their closest relatives (Rhizobium etli and Rhizobium phaseoli) and 50 - 60 % relatedness to each other. These results were further supported by average nucleotide identity values, based on genome sequencing, which were 87 - 92 % with their close relatives and 87 - 88 % with each other. On the basis of these results, three novel species, Rhizobium lentis sp. nov. (type strain BLR27T =LMG28441T =DSMZ29286T), Rhizobium bangladeshense sp. nov. (type strain BLR175T = LMG 28442T = DSMZ 29287T) and Rhizobium binae sp. nov. (type strain BLR195T =LMG28443T =DSM29288T) are proposed. These species share common nodulation genes (nodA, nodC and nodD) that are similar to those of the symbiovar viciae.Key words: Rhizobia, lentil, DNA-DNA relatedness, genome sequencing, average nucleotide identity.