Microvirga flavescens sp. nov., a novel bacterium isolated from forest soil and emended description of the genus Microvirga.

An aerobic, Gram-stain-negative, motile and rod-shaped bacterium, designated c27j1, was isolated from a forest soil sample from the Chebaling National Nature Reserve in Guangdong Province, China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain c27j1 belongs to the genus Microvirga and was most closely related to Microvirga aerophila DSM 21344 (97.7 %) and Microvirga subterranea DSM 14364 (96.7 %). The average nucleotide identity and digital DNA-DNA hybridization values based on whole genome sequences of strain c27j1 and M. aerophila DSM 21344 were 77.2 and 22.4 %, respectively. It contained ubiquinone 10 as the predominant quinone, and C19 : 0 cycloω8c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) as the major fatty acids. The polar lipids consisted of phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, phosphatidylethanolamine and two unidentified glycolipids. The genomic DNA G+C content based on the whole genome sequence was 62.2 mol%. Phenotypic, chemotaxonomic, phylogenetic and genomic analyses suggested that strain c27j1 should represent a novel species of the genus Microvirga, for which the name Microvirgaflavescens sp. nov. is proposed. The type strain is c27j1 (=GDMCC 1.1356=KCTC 62433). The description of the genus Microvirga is also emended, including the major fatty acids, genome size and DNA G+C content.