Bosea caraganae sp. nov. a new species of slow-growing bacteria isolated from root nodules of the relict species Caragana jubata (Pall.) Poir. originating from Mongolia.

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 98.7-98.8 %). The recA gene of strain RCAM04680T showed the highest sequence similarity to the type strain B. lupini LMG 26383T (95.4 %), while its atpD gene was closest to that of B. lathyri LMG 26379T (94.4 %). The ITS, dnaK and gyrB sequences of this isolate were most similar to the B. vaviloviae LMG 28367T (86.8 % for ITS, 90.4 % for the other genes). The most abundant fatty acid was C18 : 1ω7c (40.8 %). The whole genomes of strains RCAM04680T and RCAM04685 were identical (100 % average nucleotide identity). The highest average nucleotide identity value (82.8 %) 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.

Phyllobacterium zundukense sp. nov., a novel species of rhizobia isolated from root nodules of the legume species Oxytropis triphylla (Pall.) Pers.

Gram-negative strains Tri-36, Tri-38, Tri-48T and Tri-53 were isolated from root nodules of the relict legume Oxytropis triphylla (Pall.) Pers. originating from Zunduk Cape (Baikal Lake region, Russia). 16S rRNA gene sequencing showed that the novel isolates were phylogenetically closest to the type strains Phyllobacterium sophorae LMG 27899T, Phyllobacterium brassicacearum LMG 22836T, Phyllobacterium endophyticum LMG 26470T and Phyllobacterium bourgognense LMG 22837T while similarity levels between the isolates and the most closely related strain P. endophyticum LMG 26470T were 98.8-99.5 %. The recA and glnII genes of the isolates showed highest sequence similarities with P. sophorae LMG 27899T (95.4 and 89.5 %, respectively) and P. brassicacearum LMG 22836T (91.4 and 85.1 %, respectively). Comparative analysis of phenotypic properties between the novel isolates and the closest reference strains P. sophorae LMG 27899T, P. brassicacearum LMG 22836T and P. endophyticum LMG 26470T was performed using a microassay system. Average nucleotide identities between the whole genome sequences of the isolates Tri-38 and Tri-48T and P. sophorae LMG 27899T, P. brassicacearum LMG 22836T and P. endophyticum LMG 26470T ranged from 79.23 % for P. endophyticum LMG 26470T to 85.74 % for P. sophorae LMG 27899T. The common nodABC genes required for legume nodulation were absent from strains Tri-38 and Tri-48T, although some other symbiotic nod and fix genes were detected. On the basis of genotypic and phenotypic analysis, a novel species, Phyllobacterium zundukense sp. nov. (type strain Tri-48T=LMG 30371T=RCAM 03910T), is proposed.