A Gram-stain-negative, cocci or short rod-shaped, yellow-pigmented bacterium, designated strain S2-4-2T, was isolated from coastal sediment of Spartina alterniflora in Quanzhou Bay, PR China. Growth was observed at 15-40 °C (optimum, 30 °C) and pH 6.0-8.0 (optimum, pH 7.0). Strain S2-4-2T tolerated 0-10 % NaCl (optimum, 1 %). The 16S rRNA gene of strain S2-4-2T showed highest sequence similarity to Croceicoccus pelagius Ery9T (98.2 %), followed by Croceicoccus naphthovorans PQ-2T, Croceicoccus marinus E4A9T and Croceicoccus mobilis Ery22T (97.6%, 96.3 and 96.3 %, respectively). Phylogenetic analysis based on 16S rRNA gene sequences and phylogenomic analysis based on 92 up-to-date bacterial core gene sets indicated that strain S2-4-2T forms a distinct monophyletic branch affiliated to the genus Croceicoccus. The average nucleotide identity value between strain S2-4-2T and its close relatives were estimated to be 74.8-85.7 %. The respiratory quinone was found to be Q-10. The predominant fatty acids (>10 %) were identified as summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and summed feature 3 (C16 : 1ω7c and C16 : 1ω6c). The polar lipids were identified as phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and an unidentified phospholipid. The draft genome size of strain S2-4-2T was 3.5 Mb with a genomic G+C content of 63.0 mol%. Based on these results, strain S2-4-2T is concluded to represent a novel species within the genus Croceicoccus, for which the name Croceicoccus sediminis sp. nov. is proposed with the type strain S2-4-2T (=MCCC 1K03706T=KCTC 72146T).
Keywords: Croceicoccus sediminis; coastal sediment; polyphasic taxonomy.