Croceicoccus hydrothermalis sp. nov., isolated from shallow- sea hydrothermal system off Kueishantao Island

A Gram- stain-negative, strictly aerobic, non-motile, ovoid or short -rod shaped, orange-pigmented bacterial strain, designated as strain JLT1T, was isolated from seawater of the shallow -sea hydrothermal system, near Kueishantao Islet. Growth was observed at 5-45? (optimum, 30 ?) and pH 5.0-11.0 (optimum, pH 7.0). The salinity range for growth was 0-12 % (optimum, 2-4 %) (w/v) NaCl. JLT1(T) contained ubiquinone- 10 as the main respiratory quinone. Iso-C-12:0, summed feature 3 (C-16:1 omega 7c/omega 6c) and summed feature 8 (C-18:1 omega 6c/omega 7c) were identified as the major cellular fatty acids. Polar lipids included diphosphatidylg-lycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified phospholipids, eight unidentified glycolipids and an unidentified lipid. The 16S rRNA gene of JLT1(T) shared the greatest similarity (96.31 %) with those of Croceicoccus pelagius Ery9(T) and Croceicoccus ponticola GM-16(T). The draft genome size of JLT1(T) is 3.56 Mb, with 3578 potential genes and a genomic DNA G+C content of 63.24 mol %. Average nucleotide identity and digital DNA-DNA hybridization values of JLT1(T) compared with C. pelagius Ery9(T), C. ponticola GM-16(T), Croceicoccus sediminis S2-4-2(T), Croceicoccus mobilis Ery22(T) and Croceicoccus marinus E4A9(T) were 74.5, 73.9, 74.4, 74.3 and 74.8 % and 20.6, 19.2, 20.0, 20.5 and 19.8%, respectively. On the basis of these phylogenetic, chemotaxonomic and phenotypic features, JLT1(T) is concluded to represent a novel species of the genus Croceicoccus, for which the name Croceicoccus hydrothermalis sp. nov. is proposed. The type strain is JLT1(T) (=CGMCC 1.15786(T) =JCM 31508T).