ABSTRACT
Two Gram-stain-negative strains, RCAM04680T and RCAM04685, were isolated from root nodules of the relict legume Caragana jubata (Pall.) Poir. originating from the south-western shore of Lake Khuvsgul (Mongolia). The 16S rRNA gene (rrs) sequencing data showed that these novel isolates belong to the genus Bosea and are phylogenetically closest to the type strains Bosea lathyri LMG 26379T, Bosea vaviloviae LMG 28367T, Bosea massiliensis LMG 26221T and Bosea lupini LMG 26383T (the rrs-similarity levels were 98.7-98.8â%). The recA gene of strain RCAM04680T showed the highest sequence similarity to the type strain B. lupini LMG 26383T (95.4â%), while its atpD gene was closest to that of B. lathyri LMG 26379T (94.4â%). The ITS, dnaK and gyrB sequences of this isolate were most similar to the B. vaviloviae LMG 28367T (86.8â% for ITS, 90.4â% for the other genes). The most abundant fatty acid was C18â:â1ω7c (40.8â%). The whole genomes of strains RCAM04680T and RCAM04685 were identical (100â% average nucleotide identity). The highest average nucleotide identity value (82.8â%) was found between the genome of strain RCAM04680T and B. vaviloviae LMG 28367T. The common nodABC genes required for legume nodulation were absent in both strains; however, some other symbiotic nol, nod, nif and fix genes were detected. Based on the genetic study, as well as analyses of the whole-cell fatty acid compositions and phenotypic properties, a new species, Boseacaraganae sp. nov. (type strain RCAM04680T (=LMG 31125T), is proposed.