e-Wei Xu

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)).

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.

Pseudohongiellanitratireducens sp. nov., isolated from seawater, and emended description of the genus Pseudohongiella.

Two Gram-stain-negative, aerobic, motile by a single polar flagellum and rod-shaped strains, designated SCS-49T and SCS-111, were isolated from seawater of the South China Sea. The two strains grew at 4-35 °C, with 0.5-7.5 % (w/v) NaCl and at pH 6.5-9.0 and were able to reduce nitrate. Q-8 was the sole ubiquinone. The major fatty acids of the two strains were C16 : 0, C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phospoglycolipid, three unidentified glycolipids, five unidentified phospholipids and two to three unidentified lipids. The isolates formed a stable clade with Pseudohongiella acticola and Pseudohongiella spirulinae based on phylogenetic analysis of 16S rRNA gene sequences. Strains SCS-49T and SCS-111 exhibited 16S rRNA gene sequence similarity values of 97.2 and 96.0 % with respect to the type strains of P. acticola and P. spirulinae, respectively. The average nucleotide diversity and in silico DNA-DNA hybridization values between strain SCS-49T and P. acticola KCTC 42131T were 71.4 and 25.1 %, respectively and the values between strain SCS-49T and SCS-111 were 99.9 and 99.2 %, respectively. Based upon the phenotypic, chemotaxonomic and genetic data, strains SCS-49T and SCS-111 represent a novel species in the genus Pseudohongiella, for which the name Pseudohongiella nitratireducens sp. nov. is proposed. The type strain is SCS-49T (=CGMCC 1.15425T=KCTC 52155T=MCCC 1K03186T).

Molecular cloning and characterization of a novel splice variant of human ZNF300 gene, which expressed highly in testis: Short Communication

Zinc finger protein, one of the most important transcription factors, plays an essential role in regulating gene expression. C2H2 type zinc protein with KRAB domain contains two parts, one is C2H2 zinc finger motif which is use to binding to the DNA, while the other is KRAB associated box which mostly performs as a transcription repressor. In this study, we report the cloning and characterization of a novel splice variant of the human ZNF300 gene (ZNF300-B). The ZNF300-B gene cDNA is 2293 bp in length, encoding a putative protein with 619 amino acid residues. ZNF300-B gene is mapped to chromosome 5q32–5q33 with seven exons. Reverse transcription polymerase chain reaction (RT-PCR) analysis showed that ZNF300-B and ZNF-300 were expressed highly in human testis.