A Gram-stain-negative, non-motile, ovoid or short rod shaped and aerobic marine bacterium, designated as strain LXJ103T, was isolated from a coastal phytoplankton bloom in Xiamen, PR China. Cells were oxidase- and catalase-positive. Strain LXJ103T grew at 4–40 °C (optimum, 28–37 °C), at pH 6–10 (optimum, pH 8.5) and with 1–15 % (w/v) NaCl (optimum, 3 %). The major cellular fatty acids (>10 %) were iso-C18 : 1  ω7c/iso-C18 : 1  ω6c (70.2 %) and C16 : 0 (10.3 %). The following polar lipids were found to be present: phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and five unknown glycolipids. The predominant respiratory quinone was ubiquinone-10. Strain LXJ103T exhibited the highest 16S rRNA gene sequence similarity to Roseovarius litorisediminis D1-W8T (96.97 %). The phylogenetic trees based on 16S rRNA gene sequences showed that strain LXJ103T was a member of the genus Roseovarius . The draft genome size of strain LXJ103T is 3.05 Mb with a genomic G+C content of 61.22 mol%. The digital DNA–DNA genome hybridization value of strain LXJ103T compared with the most similar type strain R. litorisediminis CECT 8287T was 18.80 %. The average nucleotide identity value between strain LXJ103T and R. litorisediminis CECT 8287T was 72.60 %. On the basis of polyphasic data, strain LXJ103T represents a novel species of the genus Roseovarius , for which the name Roseovarius carneus sp. nov. is proposed. The type strain is LXJ103T (=CGMCC 1.19168T=MCCC 1K06527T=JCM 34778T).

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°C (optimum, 30 °C) and pH 5.0–11.0 (optimum, pH 7.0). The salinity range for growth was 0–12 % (optimum, 2–4 %) (w/v) NaCl. JLT1T contained ubiquinone-10 as the main respiratory quinone. Iso-C12 : 0, summed feature 3 (C16 : 1ω7c/ω6c) and summed feature 8 (C18 : 1ω6c/ω7c) were identified as the major cellular fatty acids. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified phospholipids, eight unidentified glycolipids and an unidentified lipid. The 16S rRNA gene of JLT1T shared the greatest similarity (96.31 %) with those of Croceicoccus pelagius Ery9T and Croceicoccus ponticola GM-16T. The draft genome size of JLT1T 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 JLT1T compared with C. pelagius Ery9T, C. ponticola GM-16T, Croceicoccus sediminis S2-4-2T, Croceicoccus mobilis Ery22T and Croceicoccus marinus E4A9T 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, JLT1T 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 JLT1T (=CGMCC 1.15786T =JCM 31508T).

Strain designated TK19116T was isolated from the shallow-sea hydrothermal systems off Kueishantao Island in Taiwan, China. The bacterium was Gram-stain-negative, aerobic, oxidase-positive and catalase-positive. Cells of the strain TK19116T were short-rod-shaped and non-motile. The results of phylogenetic analysis of 16S rRNA gene sequences indicated that strain TK19116T belonged to the genus Paracoccus , with the highest sequence similarity to Paracoccus alkanivorans 4-2T (97.1 %). The average nucleotide identity values between the strain TK19116T with Paracoccus alkanivorans 4-2T, Paracoccus zhejiangensis J6T, Paracoccus siganidrum M26T and Paracoccus tegillarcae BM15T were 75.3, 76.7, 76.7 and 75.8%, respectively. The digital DNA–DNA hybridization value between the strain TK19116T with Paracoccus alkanivorans 4-2T, Paracoccus zhejiangensis J6T, Paracoccus siganidrum M26T and Paracoccus tegillarcae BM15T were 19.7, 20.3, 20.5 and 20.0%, respectively. The main respiratory quinone of strain TK19116T was ubiquinone 10. The polar lipids include aminolipid, phosphatidylcholine, diphosphatidylglycerol, glycolipid, phosphatidylglycerol and phospholipid. The principal fatty acid of strain TK19116T was summed feature 8 (C18 : 1  ω6c and/or C18 : 1  ω7c). The G+C content of the chromosomal DNA was 64.2 %. The combination of the results of the phylogenetic, phenotypic and chemotaxonomic analysis, strain TK19116T represents a novel species of the genus Paracoccus , for which the name Paracoccus albicereus sp. nov. is proposed. The type strain is TK19116T (= MCCC 1K08025T=JCM 35527T).