Yue-Hong Wu

Marinobacter pelagius sp. nov., a moderately halophilic bacterium

A Gram-negative, aerobic, neutrophilic, moderately halophilic bacterial strain, HS225(T), was isolated from seawater samples around the Zhoushan Archipelago, Zhejiang Province, China. The isolate grew optimally in media with 5.0 % NaCl, at pH 7.0-8.0 and at 25-30 degrees C. The predominant fatty acids were C(16 : 0)omega9c, C(16 : 0), C(12 : 0) 3-OH and C(18 : 1)omega9c. The genomic DNA G+C content was 59.0 mol%. Based on 16S rRNA gene sequence analysis, the isolate was found to be affiliated to the genus Marinobacter. Strain HS225(T) exhibited closest phylogenetic affinity to Marinobacter koreensis DD-M3(T) (98.1 % 16S rRNA gene sequence similarity). DNA-DNA relatedness data and DNA G+C contents as well as physiological and biochemical test results allowed the genotypic and phenotypic differentiation of strain HS225(T) from closely related species. Therefore, it is proposed that strain HS225(T) represents a novel species of the genus Marinobacter, for which the name Marinobacter pelagius sp. nov. is proposed. The type strain is HS225(T) (=CGMCC 1.6775(T) =JCM 14804(T)).

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 E4A9T, 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-C15:0, iso-C14:0 and iso-C15:0 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 E4A9T 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 E4A9T (=CGMCC 1.6776T=JCM 14846T).

Microbulbifer donghaiensis sp. nov., isolated from marine sediment of the East China Sea.

A Gram-negative, aerobic, neutrophilic, rod-shaped bacterium, designated strain CN85(T), was isolated from a sediment sample collected from the East China Sea and was subjected to a polyphasic taxonomic characterization. This isolate grew in the presence of 0.5-6.0 % (w/v) NaCl and at 20-40 degrees C; optimum growth was observed with 3 % (w/v) NaCl and at 35 degrees C. Chemotaxonomic analysis showed that Q-8 was the predominant respiratory quinone and that iso-C(15 : 0), iso-C(11 : 0) 3-OH, iso-C(17 : 1)omega9c, iso-C(17 : 0), iso-C(11 : 0) and C(16 : 0) were the major fatty acids. The G+C content of the genomic DNA was 57.8 mol%. On the basis of 16S rRNA gene sequence analysis, the isolate was affiliated to the genus Microbulbifer. Strain CN85(T) exhibited most phylogenetic affinity with respect to the type strain of Microbulbifer maritimus (97.0 % sequence similarity) and showed less than 97 % sequence similarity with respect to other described Microbulbifer species with known 16S rRNA gene sequences. The DNA-DNA hybridization between strain CN85(T) and M. maritimus JCM 12187(T) was 44 %. On the basis of phenotypic and genotypic data, strain CN85(T) represents a novel species of the genus Microbulbifer, for which the name Microbulbifer donghaiensis sp. nov. is proposed. The type strain is CN85(T) (=CGMCC 1.7063(T) =JCM 15145(T)).

Pseudidiomarina donghaiensis sp. nov. and Pseudidiomarina maritima sp. nov., isolated from the East China Sea

Two Gram-negative, aerobic, motile, rod-shaped bacteria, designated strains 908033(T) and 908087(T), were isolated from a seawater sample collected from the East China Sea. Chemotaxonomic characteristics of the two isolates included the presence of iso-C(15 : 0), iso-C(17 : 0) and iso-C(17 : 1)omega9c as the major cellular fatty acids and Q-8 as the predominant ubiquinone. The genomic DNA G+C contents of strains 908033(T) and 908087(T) were 45.5 and 45.2 mol%, respectively. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the new isolates were related to members of the genus Pseudidiomarina, showing levels of similarity of 95.8-96.6 % with the type strains of recognized species of the genus. The results of DNA-DNA hybridization experiments among these two isolates and Pseudidiomarina sediminum CICC 10319(T), in combination with chemotaxonomic and phenotypic data, demonstrated that the new isolates represent two novel species of the genus Pseudidiomarina, for which the names Pseudidiomarina donghaiensis sp. nov. (type strain 908033(T)=CGMCC 1.7284(T)=JCM 15533(T)) and Pseudidiomarina maritima sp. nov. (type strain 908087(T)=CGMCC 1.7285(T)=JCM 15534(T)) are proposed.

Microbacterium profundi sp. nov., isolated from deep-sea sediment of polymetallic nodule environments.

A Gram-positive, aerobic, neutrophilic and rod-shaped bacterium, strain Shh49(T), was isolated from a deep-sea sediment sample collected from the East Pacific polymetallic nodule region. The strain was able to grow within a temperature range of 4-35 degrees C and tolerated up to 7.5 % (w/v) NaCl. Strain Shh49(T) was characterized chemotaxonomically by having MK-12 and MK-13 as predominant isoprenoid quinones, anteiso-C(15 : 0), iso-C(15 : 0), iso-C(16 : 0) and anteiso-C(17 : 0) as major fatty acids and ornithine as cell-wall diamino acid. The genomic DNA G+C content was 66.8 mol%. On the basis of 16S rRNA gene sequence similarities, the closest phylogenetic neighbours were the type strains of Microbacterium phyllosphaerae (98.3 %) and Microbacterium keratanolyticum (98.0 %), but strain Shh49(T) could be clearly distinguished from its phylogenetic relatives with reference to a broad range of physiological and biochemical markers. DNA-DNA relatedness of strain Shh49(T) with M. phyllosphaerae DSM 13468(T) and M. keratanolyticum DSM 8606(T) was 56 and 31 %, respectively. On the basis of phenotypic and genotypic data presented in this study, strain Shh49(T) represents a novel species of the genus Microbacterium, for which the name Microbacterium profundi sp. nov. is proposed. The type strain is Shh49(T) (=CGMCC 1.6777(T) =JCM 14840(T)).

Halomonas salifodinae sp. nov., a halophilic bacterium isolated from a salt mine in China.

A Gram-negative, aerobic, motile, halophilic bacterium, designated strain BC7(T), was isolated from a salt mine in north-western China and was subjected to a polyphasic taxonomic characterization. The isolate was able to grow in the presence of 0.5-20 % (w/v) NaCl and at pH 6.0-9.0 and 4-48 degrees C; optimum growth was observed with 3 % (w/v) NaCl and at pH 7.0 and 30 degrees C. Cells were long rods, 0.8-1.2 microm wide and 4.0-6.0 microm long. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(16 : 0)omega7c. The DNA G+C content was 65.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BC7(T) belonged to the genus Halomonas and showed highest sequence similarity to the type strain of Halomonas pacifica (99.2 %). Levels of DNA-DNA relatedness between strain BC7(T) and H. pacifica CGMCC 1.2314(T) and Halomonas taeanensis DSM 16463(T) were 51 and 38 %, respectively. On the basis of phenotypic and genotypic data, strain BC7(T) is considered to represent a novel species of the genus Halomonas, for which the name Halomonas salifodinae sp. nov. is proposed. The type strain is BC7(T) (=CGMCC 1.6774(T) =JCM 14803(T)).

Culturable halophilic archaeal diversity of Ayakekumu salt lake located in Xinjiang, China

Abstract Molecular diversity of halophilic archaea from Ayakekumu salt lake was investigated by the polymerase chain reaction (PCR) amplification and culture methods. 19 water samples and 15 soil samples were taken from 19 sites within Ayakekumu salt lake in winter and spring. Under aerobic culture conditions, some halophilic microorganisms were isolated by five different media. The 16S rRNA gene sequences of 62 red strains were amplified by using PCR, determined by the DNA sequencer and analyzed through the BLASTn program subsequently. Results revealed that all sequences belonged to six genera grouped within the Halobacteriaceae. Mostly 16S rRNA gene sequences related to the genera Halorubrum (47%) and Natrinema (24%) were detected. Subsequent analysis by using Shannon index indicated that cultured halophilic archaeal diversities are not significantly different between winter and spring samplings in Ayakekumu salt lake. Similarity values of haloarchaeal 16S rRNA gene sequences to known sequences were less than 97%, suggesting the presence of two novel taxa. In addition, taxonomic characteristics of Natrinema altunense and Halobiforma lacisalsi isolated from Ayakekumu salt lake had been described previously. The discovery of the novel species provides new opportunity to further examine the diversity of these halophilic microorganisms in Ayakekumu salt lake.

Vibrio hangzhouensis sp. nov., isolated from sediment of the East China Sea

Strain CN83T, a Gram-negative, aerobic, rod-shaped bacterium, was isolated from sediment of the East China Sea. The isolate was catalase- and oxidase-positive and cells were motile by means of polar flagella. The DNA G+C content was 44.9 mol%. The major fatty acids were C16:1omega7c and/or iso-C15:0 2-OH, C16:0, C18:1omega7c, C14:0 and C12:0. 16S rRNA gene sequence analysis showed that strain CN83T belonged to the genus Vibrio and had the highest sequence similarity to Vibrio agarivorans (98.4%) and Vibrio campbellii (97.8%). Phylogenetic analysis revealed that strain CN83T formed a monophyletic clade adjacent to the type strain of V. agarivorans. The DNA-DNA hybridization values of strain CN83T with V. agarivorans DSM 13756T and V. campbellii DSM 19270T were 44.6 and 25.5%, respectively. On the basis of the phenotypic and genotypic data, strain CN83T represents a novel species of the genus Vibrio, for which the name Vibrio hangzhouensis sp. nov. is proposed. The type strain is CN83T (=CGMCC 1.7062T=JCM 15146T).