Aquipuribacter nitratireducens sp. nov., isolated from a soil sample of a mud volcano.

A novel Gram-stain-positive, coccoid, non-motile bacterium, designated strain AMV4T, was isolated from a soil sample collected from a mud volcano located in the Andaman Islands, India. The colony was pale orange. Strain AMV4T was positive for oxidase, aesculinase, lysine decarboxylase and ornithine decarboxylase activities and negative for amylase, catalase, cellulase, protease, urease and lipase activities. 16S rRNA gene sequence analysis indicated that strain AMV4T was a member of the order Actinomycetales and was closely related to Aquipuribacter hungaricus with a sequence similarity of 97.13% (pairwise alignment). Phylogenetic analyses showed that strain AMV4T clustered with Aquipuribacter hungaricus and was distantly related to the other genera of the family Intrasporangiaceae. DNA-DNA hybridization between strains AMV4T and Aquipuribacter hungaricus IV-75T showed a relatedness of 28%. The predominant cellular fatty acids were iso-C15 : 0 (6.9%), anteiso-C15 : 0 (25.3%), C16 : 0 (12.9%), anteiso-C16 : 0 (5.6%), C18 : 1ω9c (19.8%) and C18 : 3ω6,9,12c (9.1%). The diagnostic diamino acid in the cell-wall peptidoglycan of strain AMV4T was meso-diaminopimelic acid. Strain AMV4T contained MK-10(H4) as the predominant respiratory quinone. The polar lipids consisted of phosphatidylglycerol, one unidentified glycolipid, two unidentified phospholipids and five unidentified lipids. The DNA G+C content of strain AMV4T was 74.3 mol%. Based on data from this taxonomic study using a polyphasic approach, it is proposed that strain AMV4T represents a novel species of the genus Aquipuribacter, with the suggested name Aquipuribacter nitratireducens sp. nov. The type strain is AMV4T ( = CCUG 58430T = DSM 22863T = NBRC 107137T).