Shimia biformata sp. nov., isolated from surface seawater, and emended description of the genus Shimia Choi and Cho 2006

Abstract

A novel, Gram-staining-negative, non-flagellated, oval or short-rod-shaped, strictly aerobic and non-spore-forming marine bacterium, designated strain CC-AMW-C(T), was isolated from coastal surface seawater in Kending County, Taiwan. Cells of strain CC-AMW-C(T) displayed unusual morphology and formed colourless or beige colonies on marine agar. The isolate shared pairwise 16S rRNA gene sequence similarities of 97.2 and 97.1 % with Shimia marina BCRC 80068(T) and Shimia isoporae BCRC 80085(T), respectively, and established a discrete phyletic lineage closely associated with the members of the genus Shimia. DNA-DNA hybridization values indicated <18.2 % genomic relatedness with species of the genus Shimia. The polar lipid profile of strain CC-AMW-C(T) comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, two unidentified aminolipids, four unidentified lipids and an unidentified phospholipid. The predominant fatty acids were C18 : 1ω7c and/or C18 : 1ω6c (summed feature 8; 75.5 %). The DNA G+C content was 61.2 mol%. The predominant respiratory quinone was ubiquinone Q-10 and the major polyamine was cadaverine. The chemotaxonomic evidence, including extraordinary amounts of C18 : 1ω7c and/or C18 : 1ω6c, major polar lipids, polyamine, quinone and DNA G+C contents of CC-AMW-C(T), was in line with that of the members of the genus Shimia. Thus, strain CC-AMW-C(T) should be classified as a novel species of the genus Shimia, for which the name Shimia biformata sp. nov. is proposed. The type strain is CC-AMW-C(T) ( = JCM 18818(T) = BCRC 80548(T)). An emended description of the genus Shimia is also proposed.