Gracilimonas halophila sp. nov., isolated from a marine solar saltern

A Gram-stain-negative and facultatively anaerobic bacterium, designated WDS2C40T, was isolated from a marine solar saltern in Weihai, China. Cells of strain WDS2C40T were 0.4-0.5 µm wide and 4.0-9.0 µm long, catalase-positive and oxidase-negative. Strain WDS2C40T was tolerant to moderate salt concentrations. Growth occurred at 20-42 °C (optimum, 37-40 °C), at pH 7.0-8.5 (optimum, 7.5-8.0) and with 2-16 % (w/v) NaCl (optimum, 6-8 %). A phylogenetic analysis of the 16S rRNA gene indicated that strain WDS2C40T was a member of the genus Gracilimonas within the family Balneolaceae. The most closely related neighbour was Gracilimonas rosea JCM 18898T (95.92 % similarity). The major respiratory quinone of strain WDS2C40T was menaquinone MK-7, and the dominant fatty acids were iso-C13 : 0, iso-C15 : 0 and summed feature 3. The major polar lipids were diphosphatidylglycerol, one kind of glycolipid and two unidentified phospholipids. The genomic DNA G+C content was 41.7 mol%. Based on this polyphasic taxonomic study, strain WDS2C40T is considered to represent a novel species in the genus Gracilimonas, for which the name Gracilimonas halophila sp. nov. is proposed. The type strain is WDS2C40T (=KCTC 52042T=MCCC 1H00135T).