Paracoccus xiamenensis sp. nov., isolated from seawater on the Xiamen

Strain 12-3 T was isolated from seawater of the Guanyinshan Coast, Xiamen, Fujian Province, PR China. The bacterium was Gram-stain-negative, rod-shaped, aerobic, oxidase-positive and catalase-negative. Growth of strain 12-3 T occurred at 10–37 °C (optimum, 20–30 °C), at pH 5.0–11.0 (optimum, pH 7.0–8.0) and at a salinity range of 0–10 % (optimum, 3–5 %). The results of phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain 12-3 T belonged to the genus Paracoccus and had the highest sequence similarity to Paracoccus lutimaris HDM-25 T (97.4 %), followed by Paracoccus isoporae SW-3 T (96.9 %), Paracoccus caeni MJ17 T (96.9 %), Paracoccus pacificus F14 T (96.8 %) and other species in the genus Paracoccus (95.3–96.5 %). The average nucleotide identity (ANI) and DNA–DNA hybridization (DDH) values between strain 12-3 T and P. lutimaris HDM-25 T were 76.1 and 17.0 %, respectively. ANI and DDH values between strain 12-3 T and P. isoporae SW-3 T were 78.9 and 18.2 %, respectively. The principal fatty acid of strain 12-3 T was summed feature 8 (C 18 : 1  ω 6 c / ω 7 c ) and C 18 : 0 . The respiratory quinone of strain 12-3 T was Q10. The polar lipids included phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid. The G+C content of the chromosomal DNA was 63.9 mol%. The combination of the results of the phylogenetic, phenotypic and chemotaxonomic analyses, and its low ANI and DDH values indicate that strain 12-3 T represents a novel species of the genus Paracoccus , for which the name Paracoccus xiamenensis sp. nov. is proposed. The type strain is 12-3 T (=MCCC 1A16381 T =KCTC 72687 T ).