Microvirga calopogonii sp. nov., a novel alphaproteobacterium isolated from a root nodule of Calopogonium mucunoides in Southwest China

Microvirga roseola sp. nov. and Microvirga lenta sp. nov., isolated from Taklamakan Desert soil

Two Gram-negative, rod-shaped, non-spore-forming bacteria, designated SM9T and SM2T, were isolated from Taklamakan Desert soil samples. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strains SM9T and SM2T had the highest sequence similarity to the type strains Microvirga indica BCRC 80972T and Microvirga soli NBRC 112417T with similarity values of 98.2 and 97.7 %, respectively, and Microvirga was among the predominant genera in the desert soil. The draft genomes of these two strains were 4.56 Mbp (SM9T) and 5.08 Mbp (SM2T) long with 65.1 mol% (SM9T) and 63.5 mol% (SM2T) G+C content. To adapt to the desert environment, these two strains possessed pathways for the synthesis of stress metabolite trehalose. The major fatty acids (>5 %) included C18 : 1 ω9c in SM2T, but C16 : 0, C18 : 0 and C19 : 0 cyclo ω8c in SM9T, while the major menaquinone was ubiquinone 10 in both strains. The major polar lipids of SM9T and SM2T were phosphatidylglycerol, phosphatidylethanolamine and phospholipid. The average nucleotide identity and digital DNA–DNA hybridization results further indicated that strains SM9T and SM2T were distinguished from phylogenetically related species and represented two novel species within the genus Microvirga , for which the names Microvirga roseola sp. nov. (type strain SM2T=KCTC 72792T=CGMCC 1.17776T) and Microvirga lenta sp. nov. (type strain SM9T=KCTC 82729T=CCTCC AB 2021131T) are proposed.

Microvirga pudoricolor sp. nov., and Microvirga alba sp. nov., isolated from soil in South Korea

Two novel Gram-stain-negative, aerobic, rod-shaped, circular, convex, light-pink and white-colored bacterial strains BT291^T and BT350^T were isolated from soil collected in Uijeongbu city (37° 44' 55″ N, 127° 2' 20″ E) and Jeju island (33° 22' 48″ N, 126° 31' 48″ E), respectively, South Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that each of the strains BT291^T and BT350^T belong to a distinct lineages within the genus Microvirga (family Methylobacteriaceae, order Rhizobiales, class Alpha Proteobacteria, phylum Proteobacteria, kingdom Bacteria). The 16S rRNA gene sequence similarity between the two strains BT291^T and BT350^T was 97.4%. The two strains were found to have the same quinone system, with Q-10 as the major respiratory quinone. The major polar lipids of strains BT291^T and BT350^T were phosphatidylethanolamine (PE), diphosphatydilglycerol (DPG), phosphatidylcholine (PC) and phosphatidylglycerol (PG). The major cellular fatty acids of strain BT291^T were C_18:1 ω7c (58.2%) and cyclo-C_19:0 ω8c (25.7%). The major cellular fatty acids of strain BT350^T were C_18:1 ω7c (38.5%) and cyclo-C_19:0 ω8c (27.7%). Based on the polyphasic analysis (phylogenetic, chemotaxonomic and biochemical), strains BT291^T and BT350^T can be suggested as two novel bacterial species within the genus Microvirga and the proposed names are Microvirga pudoricolor and Microvirga alba, respectively. The type strain of Microvirga pudoricolor is BT291^T (= KCTC 72368^T = NBRC 114845^T) and the type strain of Microvirga alba is BT350^T (= KCTC 72385^T = NBRC 114848^T).

Draft genome and description of Microvirga mediterraneensis strain Marseille-Q2068T sp. nov., a new bacterium isolated from human healthy skin

In 2019, by culturing a skin swab from the forehead of a 70-year-old healthy woman via the culturomics method, we isolated the new bacterial strain Marseille-Q2068T (= CSUR-Q2068). Matrix-assisted desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) failed to identify this isolate. Analysis of the 16S ribosomal RNA gene and genome-to-genome comparison suggested that this taxon belongs to a novel bacterial species within the family Methylobacteriaceae in the phylum Proteobacteria. We describe here its main phenotypic characteristics, genome sequence and annotation of Microvirga mediterraneensis strain Marseille-Q2068T, a new member of the Microvirga genus, which we propose as the type strain.

International Committee on Systematics of Prokaryotes Subcommittee on the Taxonomy of Rhizobia and Agrobacteria Minutes of the closed meeting by videoconference, 17 July 2019

Minutes of the closed meeting of the ICSP Subcommittee on the Taxonomy of Rhizobia and Agrobacteria held by videoconference on 17 July 2019, and list of recent species.