Altererythrobacter aurantiacus sp. nov., isolated from deep-sea sediment.

A Gram-negative, aerobic, coccoid bacterium, strain O30(T), was isolated from a deep-sea sediment sample collected from the west Pacific. 16S rRNA gene sequence analysis revealed that this strain is affiliated with the family Erythrobacteraceae in the class Alphaproteobacteria, and is closely related to the members of the genera Erythromicrobium (96.6 %), Porphyrobacter (95.5-96.3 %), Altererythrobacter (94.1-96.2 %) and Erythrobacter (94.2-96.2 %). Phylogenetic analysis including all described species of the family Erythrobacteraceae revealed that the isolate forms a clade in the cluster of the genus Altererythrobacter. Strain O30(T) was found to grow at 4-40 °C, pH 6.0-10.0 and in the presence of 0.5-7.0 % (w/v) NaCl. Chemotaxonomic analysis revealed ubiquinones Q-8, Q-9 and Q-10 as the predominant respiratory quinones, summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C17:1 ω6c and C16:0 as major fatty acids, and diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid as the major polar lipids. The DNA G + C content was determined to be 56.9 mol %. On the basis of phenotypic and genotypic data presented in this study, strain O30(T) represents a novel species within the genus Altererythrobacter, for which the name Altererythrobacter aurantiacus sp. nov. is proposed; the type strain is O30(T) (= CGMCC 1.12762(T) = JCM 19853(T) = LMG 28110(T) = MCCC 1A09962(T)).

Alkalimicrobium pacificum gen. nov., sp. nov., a marine bacterium in the family Rhodobacteraceae.

A Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, designated strain F15T, was isolated from a deep-sea sediment of the western Pacific Ocean. The temperature, pH and NaCl ranges for growth were 4-50 °C, pH 6-11 and 0-10 % (w/v), respectively. Strain F15T showed the highest 16S rRNA gene sequence similarity to Sagittula stellata E-37T (96.4%), followed by Ponticoccus litoralis CL-GR66T (96.4%), Antarctobacter heliothermus EL-219T (96.3%) and Thalassococcus lentus YCS-24T (96.0%). Phylogenetic analysis based on 16S rRNA gene sequence data showed that strain F15T formed a lineage within the family Rhodobacteraceae of the class Alphaproteobacteria. The polar lipid profile of strain F15T comprised significant amounts of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified glycolipid and one unidentified phospholipid. The predominant cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c, 40.2%), anteiso-C15 : 0 (30.4%) and anteiso-C17 : 0 (9.7%). The genomic DNA G+C content of strain F15T was 60.2 mol% and the major respiratory quinone was Q-10. On the basis of phenotypic, phylogenetic and chemotaxonomic data, strain F15T is considered to represent a novel species of a new genus within the family Rhodobacteraceae, for which the name Alkalimicrobium pacificum gen. nov., sp. nov. is proposed. The type strain is F15T ( = LMG 28107T = JCM 19851T = CGMCC 1.12763T = MCCC 1A09948T).

Virgibacillus oceani sp. nov. isolated from ocean sediment.

A Gram-stain-positive, moderately halophilic, motile, strictly aerobic, endospore-forming, rod-shaped bacterium, strain MY11(T), was isolated from a sediment sample collected from the Western Pacific. This isolate grew in the presence of 0.5-18% (w/v) NaCl and at pH 6.0-10.0 and 15-45 °C; optimum growth was observed with 3.5% (w/v) NaCl and at pH 8.0-9.0 and 35-37 °C. Strain MY11(T) had menaquinone 7 (MK-7) as the predominant respiratory quinone and anteiso-C15:0 and anteiso-C17:0 as major fatty acids. Major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C content was 34.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences confirmed that strain MY11(T) was a member of the genus Virgibacillus, exhibiting sequence similarities of 95.3-97.6% to the type strains of recognized Virgibacillus species. Strain MY11(T) could be differentiated from recognized species of the genus Virgibacillus based on phenotypic characteristics, chemotaxonomic differences, phylogenetic analysis and DNA-DNA hybridization data. On the basis of the data presented, strain MY11(T) is considered to represent a novel species of the genus Virgibacillus, for which the name Virgibacillus oceani sp. nov. is proposed. The type strain is MY11(T) ( =LMG 28105(T) =CGMCC 1.12754(T) =MCCC 1A09973(T)).

Altererythrobacter oceanensis sp. nov., isolated from the Western Pacific.

A Gram-stain negative, ovoid-rod shaped, strictly aerobic bacterium, strain Y2(T), was isolated from a deep-sea sediment of the Western Pacific. Phylogenetic and phenotypic properties of the organism indicated that it belongs to the genus Altererythrobacter. Strain Y2(T) shares highest 16S rRNA gene sequence similarity of 96.6 % with Erythrobacter jejuensis CNU001(T), followed by the type strains of recognized members of the genus Altererythrobacter (94.8-96.5 %). Strain Y2(T) forms a clade with E. jejuensis CNU001(T) in the cluster of species of the genus Altererythrobacter. Growth of strain Y2(T) was observed at 4-40 °C (optimum, 35-37 °C), at pH 6.0-10.0 (optimum, pH 7.0-8.0) and in the presence of 0-5 % (w/v) NaCl (optimum, 2-3 %). The major cellular fatty acids were found to be C17:1 ω6c (41.5 %), summed feature 8 (C18:1 ω7c and/or C18:1 ω6c; 17.2 %), C17:1 ω8c (11.0 %) and C15:0 2OH (8.1 %). The major respiratory quinone was determine to be ubiquinone 10 (Q-10). The polar lipid analysis indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, one sphingoglycolipid, three unidentified phospholipids, two unidentified glycolipids, two unidentified aminolipids and three unknown lipids. The DNA G + C content of the type strain is 60.0 mol %. On the basis of the data from the polyphasic characterization, strain Y2(T) represents a novel species, for which the name Altererythrobacter oceanensis sp. nov. is proposed. The type strain is Y2(T) (=CGMCC 1.12752(T) =LMG 28109(T)).

Paracoccus pacificus sp. nov., isolated from the Western Pacific Ocean.

A Gram-stain negative, short rod-shaped, non-motile, catalase- and oxidase-positive, aerobic bacterium, designated F14(T), was isolated from the Western Pacific Ocean. Phylogenetic and phenotypic properties of the organism supported that it belongs to the genus Paracoccus. The levels of 16S rRNA gene sequences similarity between strain F14(T) and other type strains of recognized members of the genus Paracoccus were 93.6-96.5%. Growth of strain F14(T) was observed at 4-40 °C (optimum, 28-30 °C), pH 6.0-10.0 (optimum, pH 7.0-8.0) and in the presence of 0-7% (w/v) NaCl (optimum, 1-2%). The major cellular fatty acid was summed feature 8 (C(18:1)ω6c and/or C(18:1)ω7c). The major respiratory quinone was ubiquinone-10. The polar lipid pattern indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and three unknown lipids. The DNA G+C content was 61.4 mol%. On the basis of polyphasic characterization, strain F14(T) represents a novel species, for which the name Paracoccus pacificus sp. nov. is proposed. The type strain is F14(T) (=CGMCC 1.12755(T)=LMG 28106(T)=MCCC 1A09947(T)).

Sporosarcina siberiensis sp. nov., isolated from the East Siberian Sea.

A Gram-stain positive, non-motile, rod-shaped bacterium, designated strain 1111S-42(T), was isolated from the East Siberian Sea. The organism was found to grow at 4-30 °C, pH 7.0-8.5 and in 0-8 % (w/v) NaCl, with optimal growth occurring at 28 °C, pH 7.5 and in 1 % NaCl. Based on 16S rRNA gene sequence similarity studies, strain 1111S-42(T) was found to belong to the genus Sporosarcina and to be most closely related to Sporosarcina contaminans CCUG53915(T) (97.3 %) and Sporosarcina soli I80(T) (97.2 %). The main polar lipids were found to include diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant menaquinone was identified as MK-7. The major cellular fatty acids were identified as anteiso-C15:0 (34.4 %), iso-C15:0 (29.8 %) and anteiso-C17:0 (22.4 %). The DNA G+C content of strain 1111S-42(T) was determined to be 39 mol %. The values of DNA-DNA relatedness between the strain 1111S-42(T) and related type strains of the genus Sporosarcina were less than 30 %. Based on the phylogenetic analysis, along with extensive physiological and chemotaxonomic testing, we conclude that the bacterium represents a novel species of the genus Sporosarcina, for which the name Sporosarcina siberiensis sp. nov. is proposed. The type strain is strain 1111S-42(T) (=CGMCC 1.12516(T) = LMG 27494(T)).

Janibacter indicus sp. nov., isolated from hydrothermal sediment of the Indian Ocean.

A Gram-staining-positive, aerobic and non-motile strain, 0704P10-1(T), was isolated from hydrothermal sediment of the Indian Ocean. Phylogenetic, phenotypic and chemotaxonomic data for the organism supported that it belonged to the genus Janibacter. Strain 0704P10-1(T) showed 97.2-98.7% 16S rRNA gene sequence similarities to the type strains of recognized members of the genus Janibacter. It contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall. MK-8(H4) was the only menaquinone detected. The major fatty acids were iso-C16 : 0, C17 : 1ω8c and 10-methyl C17 : 0. Meanwhile, the results of DNA-DNA hybridization studies and other physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain 0704P10-1(T) from closely related species. Thus, strain 0704P10-1(T) represents a novel species of the genus Janibacter, for which the name Janibacter indicus sp. nov. is proposed. The type strain is 0704P10-1(T) ( = LMG 27493(T) = CGMCC 1.12511(T)).

Diversity and novelty of actinobacteria in Arctic marine sediments.

The actinobacterial diversity of Arctic marine sediments was investigated using culture-dependent and culture-independent approaches. A total of 152 strains were isolated from seven different media; 18 isolates were selected for phylogenetic analysis on the basis of their 16S rRNA gene sequences. Results showed that the 18 isolates belonged to a potential novel genus and 10 known genera including Actinotalea, Arthrobacter, Brachybacterium, Brevibacterium, Kocuria, Kytococcus, Microbacterium, Micrococcus, Mycobacterium, and Pseudonocardia. Subsequently, 172 rDNA clones were selected by restriction fragment length polymorphism analysis from 692 positive clones within four actinobacteria-specific 16S rDNA libraries of Arctic marine sediments, and then these 172 clones were sequenced. In total, 67 phylotypes were clustered in 11 known genera of actinobacteria including Agrococcus, Cellulomonas, Demequina, Iamia, Ilumatobacter, Janibacter, Kocuria, Microbacterium, Phycicoccus, Propionibacterium, and Pseudonocardia, along with other, unidentified actinobacterial clones. Based on the detection of a substantial number of uncultured phylotypes showing low BLAST identities (<95 %), this study confirms that Arctic marine environments harbour highly diverse actinobacterial communities, many of which appear to be novel, uncultured species.