Three strains of Gram-negative, aerobic, neutrophilic and halophilic bacteria were isolated from samples of a salt lake on the Qinghai-Tibet Plateau and a subterranean saline well in the Si-Chuan Basin of China. These isolates, designated AJ275 T , AJ282 T and ZG16 T , were investigated using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the isolates could be affiliated to the genus Halomonas. Genomic DNA G+C contents were 65.9 mol% for AJ275 T , 56.7 mol% for AJ282 T and 57.6 mol% for ZG16 T . The results of DNA-DNA hybridizations, fatty acid analysis and physiological and biochemical tests allowed the isolates to be differentiated genotypically and phenotypically from closely related species. It is proposed that strains AJ275 T (=CGMCC 1.6493 T =JCM 14606 T =LMG 23976 T ), AJ282 T (=CGMCC 1.6494 T =JCM 14607 T =LMG 23978 T ) and ZG16 T (=CGMCC 1.6495 T =JCM 14608 T =LMG 23977 T ) represent the type strains of three novel species in the genus Halomonas: Halomonas saccharevitans sp. nov., Halomonas arcis sp. nov. and Halomonas subterranea sp. nov., respectively.

Croceicoccus marinus gen. nov., sp. nov., a yellow-pigmented bacterium from deep-sea sediment, and emended description of the family Erythrobacteraceae A Gram-negative, aerobic, neutrophilic, coccoid bacterium, strain E4A9 T , was isolated from a deep-sea sediment sample collected from the East Pacific polymetallic nodule region. 16S rRNA gene sequence analysis showed that the isolate was related to the type strain of Altererythrobacter epoxidivorans (96.0 % sequence similarity). Lower 16S rRNA gene sequence similarities were observed with other members of the genera Altererythrobacter (94.7 %), Erythrobacter (94.0-95.4 %), Erythromicrobium (94.8 %) and Porphyrobacter (94.6-95.1 %) of the family Erythrobacteraceae. Phylogenetic analysis including all described species of the family Erythrobacteraceae and several members of the family Sphingomonadaceae revealed that the isolate formed a distinct phylogenetic lineage with the family Erythrobacteraceae. Chemotaxonomic analysis revealed ubiquinone-10 as the predominant respiratory quinone, anteiso-C 15 : 0 , iso-C 14 : 0 and iso-C 15 : 0 as major fatty acids, and phosphatidylglycerol as the major polar lipid. The DNA G+C content was 71.5 mol%. The isolate contained carotenoids, but no bacteriochlorophyll a. On the basis of phenotypic and genotypic data presented in this study, strain E4A9 T represents a novel species in a new genus in the family Erythrobacteraceae for which the name Croceicoccus marinus gen. nov., sp. nov. is proposed; the type strain is E4A9 T (5CGMCC 1.6776 T 5JCM 14846 T ).The family Erythrobacteraceae (order Sphingomonadales, class Alphaproteobacteria) was proposed by Lee et al. (2005) based on a comprehensive phylogenetic analysis and, at present, it comprises four recognized genera: Altererythrobacter (Kwon et al., 2007), Erythrobacter (Shiba & Simidu, 1982), Erythromicrobium (Yurkov et al., 1994) and Porphyrobacter (Fuerst et al., 1993).Members of the family Erythrobacteraceae are aerobic and produce pink, orange or yellow pigments. Ubiquinone-10 is the major respiratory quinone. Most species in the family have been isolated from various aquatic environments such as freshwater, seawater, marine mats or sediment, a hot spring, seaweed, a starfish and coral (Shiba & Simidu, 1982; Fuerst et al., 1993;Yurkov et al., 1994; Hanada et al., 1997; Denner et al., 2002; Hiraishi et al., 2002;Rainey et al., 2003;Yoon et al., 2003Yoon et al., , 2004a Yoon et al., , b, 2005a Yoon et al., , b, 2006Ivanova et al., 2005;Kwon et al., 2007). This study focuses on the description of strain E4A9 T , isolated from a deep-sea sediment sample. Based on the taxonomic data, it is proposed that this strain be included in a new genus within the family Erythrobacteraceae.The deep-sea sediment samples were collected by a multicorer from the East Pacific polymetallic nodule region (8 u 229 380 N 145 u 239 560 W) at a depth of Abbreviation: BChl a, bacteriochlorophyll a.The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain E4A9 T is EF62399...

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-stainnegative, yellow-pigmented, non-motile and short rod-shaped. Optimal growth of strain PQ-2 T was observed at 32 6C, 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 E4A9T 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 v7c, C 17 : 1 v6c and summed feature 3 (C 16 : 1 v7c 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 (5CGMCC 1.12805 T 5NBRC 110381 T ). In addition, emended descriptions for the genus Croceicoccus and the species C. marinus are given.

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A deep-sea sediment metagenomic library was constructed and screened for lipolytic enzymes by activity-based approach. Nine novel lipolytic enzymes were identified, and the amino acid sequences shared 56% to 84% identity to other lipolytic enzymes in the database. Phylogenetic analysis showed that these enzymes belonged to family IV lipolytic enzymes. One of the lipolytic enzymes, Est6, was successfully cloned and expressed in Escherichia coli Rosetta in a soluble form. The recombinant protein was purified by Ni-nitrilotriacetic affinity chromatography column and characterized using p-nitrophenyl esters with various chain lengths. The est6 gene consisted of 909 bp that encoded 302 amino acid residues. Est6 was most similar to a lipolytic enzyme from uncultured bacterium (ACL67845, 61% identity) isolated from the South China Sea marine sediment metagenome. The characterization of Est6 revealed that it was a cold-active esterase and exhibited the highest activity toward p-nitrophenyl butyrate (C4) at 20°C and pH 7.5.