Microvirga terrestris sp. nov., and Microvirga arvi sp. nov., isolated from soil in South Korea

Two novel Gram-stain-negative, aerobic, rod shaped bacterial strains BT290^T and BT689^T were isolated from soil collected in South Korea. Colony morphologies of both strains were circular and convex while the colors of BT290^T and BT689^T were light-pink and white, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that BT290^T and BT689^T belong to a distinct lineage within the genus Microvirga (family Methylobacteriaceae, order Rhizobiales, class Alphaproteobacteria, phylum Proteobacteria, kingdom Bacteria). The 16S rR NA gene sequence similarity between two strains was 97.9%. Both strains had the similar quinone system, with ubiquinone 10 (Q-10) as the major respiratory quinone. The major polar lipids of strains BT290^T and BT689^T were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylcholine (PC), and phosphatidylglycerol (PG). The major cellular fatty acids of strain BT290^T were C_18:1 ω7c (58.2%) and C_16:0 (17.7%), while those of strain BT689^T were C_18:1 ω7c (61.8%) and C_16:0 (10.8%). On the bases of polyphasic analysis (phylogenetic, chemotaxonomic, and biochemical), strains BT290^T and BT689^T can be suggested as novel bacterial species within the genus Microvirga and the proposed names are Microvirga terrestris and Microvirga arvi, respectively. The type strain of Microvirga terrestris is BT290^T (= KCTC 72367^T = NBRC 114844^T) and the type strain of Microvirga arvi is BT689^T (= KACC 22016^T = NBRC 114858^T), respectively.