Croceicoccus naphthovorans sp. nov., a polycyclic aromatic hydrocarbons-degrading and acylhomoserine-lactone-producing bacterium isolated from marine biofilm, and emended description of the genus Croceicoccus

A polycyclic aromatic hydrocarbons-degrading and acylhomoserine-lactone-producing marine bacterium, designated strain PQ-2 T , was isolated from marine biofilm collected from a boat shell at a harbour of Zhoushan island in Zhejiang Province, PR China. Strain PQ-2 T is Gram-stain-negative, yellow-pigmented, non-motile and short rod-shaped. Optimal growth of strain PQ-2 T was observed at 32 °C, at pH 7.0 and in 2 % (w/v) NaCl. The 16S rRNA gene sequence of strain PQ-2 T showed highest similarity to Croceicoccus marinus E4A9 T (96.3 %) followed by Novosphingobium malaysiense MUSC 273 T (95.6 %) and Altererythrobacter marinus H32 T (95.6 %). Phylogenetic analysis with all species of the family Erythrobacteraceae with validly published names revealed that strain PQ-2 T formed a phyletic line with Croceicoccus marinus E4A9 T that was distinct from other members of the family Erythrobacteraceae . The sole respiratory quinone was ubiquinone 10 (Q-10). The predominant fatty acids were C 18 : 1 ω7 c , C 17 : 1 ω6 c and summed feature 3 (C 16 : 1 ω7 c and/or iso-C 15 : 0 2-OH). The genomic DNA G+C content was 61.7 mol%. In the polar lipid profile, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, one unidentified phospholipid and one sphingoglycolipid were the major compounds; and another sphingoglycolipid was present in a minor amount. Based on the genotypic and phenotypic data, strain PQ-2 T represents a novel species of the genus Croceicoccus , for which the name Croceicoccus naphthovorans sp. nov. is proposed. The type strain is PQ-2 T ( = CGMCC 1.12805 T = NBRC 110381 T ). In addition, emended descriptions for the genus Croceicoccus and the species C. marinus are given.