Virgibacillus salinus sp. nov., a moderately halophilic bacterium from sediment of a saline lake.

A novel, moderately halophilic, Gram-positive bacterium, designated strain XH-22(T), was isolated from sediment of a saline lake located near Xilinhot, Inner Mongolia Autonomous Region, China. Cells were rod-shaped, endospore-forming and motile. The isolate was able to grow in the presence of 3-20 % (w/v) total salts (optimum, 10 %, w/v), and at 15-40 degrees C (optimum, 37 degrees C) and pH 6.0-10.0 (optimum, pH 7.5). Strain XH-22(T) had diaminopimelic acid in the cell-wall peptidoglycan, MK-7 as the predominant menaquinone, and anteiso-C(15 : 0), C(16 : 0) and iso-C(14 : 0) as major fatty acids. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, a glycolipid and two unidentified phospholipids. The DNA G+C content of strain XH-22(T) was 38.8 mol%. 16S rRNA gene sequence analysis revealed that the novel strain was affiliated with the genus Virgibacillus. Levels of 16S rRNA gene sequence similarity between strain XH-22(T) and the type strains of recognized Virgibacillus species ranged from 97.6 % (with Virgibacillus carmonensis) to 94.9 % (with Virgibacillus koreensis). Levels of DNA-DNA relatedness between strain XH-22(T) and V. carmonensis DSM 14868(T) and Virgibacillus necropolis DSM 14866(T) were 32 and 28 %, respectively. Strain XH-22(T) could be differentiated from recognized Virgibacillus species based on phenotypic characteristics, chemotaxonomic differences, phylogenetic analysis and genotypic features. On the basis of these results, strain XH-22(T) is considered to represent a novel species of the genus Virgibacillus, for which the name Virgibacillus salinus sp. nov. is proposed. The type strain is XH-22(T) (=CCM 7562(T)=CECT 7439(T)=DSM 21756(T)).

Aquisalibacillus elongatus gen. nov., sp. nov., a moderately halophilic bacterium of the family Bacillaceae isolated from a saline lake.

A novel moderately halophilic, non-motile, rod-shaped bacterium was isolated from a saline lake, Lake Shangmatala, in the Inner Mongolia Autonomous Region, China. This bacterium, designated SH4sT, was strictly aerobic, catalase-positive and oxidase-negative. It grew at salinities of 3-20 % (w/v) NaCl, with an optimum at 10 % (w/v) NaCl. The cell-wall peptidoglycan was of the A4beta type, based on l-Orn-d-Asp, and the major quinone was a menaquinone with seven isoprene units (MK-7). The major fatty acids were iso-C16:0 and iso-C15:0. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a glycolipid and four different unidentified phospholipids. The DNA G+C content was 45.9 mol%. In a maximum-parsimony phylogenetic tree based on 16S rRNA gene sequences, strain SH4sT was found to belong to the family Bacillaceae and to be most closely related to members of the genera Filobacillus (95.9 % sequence similarity), Piscibacillus (95.7 %) and Tenuibacillus (95.4 %). DNA-DNA hybridization experiments revealed 10 % relatedness (12 %, reciprocally) between strain SH4sT and Filobacillus milosensis DSM 13259T, the sole species of the genus. All of these data show that strain SH4sT represents a novel genus and species in the family Bacillaceae, for which the name Aquisalibacillus elongatus gen. nov., sp. nov. is proposed. The type strain of Aquisalibacillus elongatus is SH4sT (=CCM 7366T =CECT 7149T =DSM 18090T).

Sediminibacillus halophilus gen. nov., sp. nov., a moderately halophilic, Gram-positive bacterium from a hypersaline lake.

A Gram-positive, moderately halophilic bacterium, designated strain EN8d(T), was isolated from sediment from Lake Erliannor in the Inner Mongolia Autonomous Region, China. Cells were facultatively anaerobic, rod-shaped and motile and did not display endospore formation. Isolate EN8dT grew in a complex medium supplemented with 0-20 % (w/v) marine salts (optimally at 5-7.5 %, w/v). Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain EN8dT was a member of the family Bacillaceae, belonging to a cluster with Thalassobacillus (96.3 % gene sequence similarity) and Halobacillus (95.0-96.0 %), albeit emerging as an independent lineage from members of these two genera. Strain EN8dT contained cell-wall peptidoglycan based on meso-diaminopimelic acid and possessed MK-7 as the major respiratory isoprenoid quinone. The major fatty acids were anteiso-C15:0 and anteiso-C17:0. The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. The DNA G+C content was 47.5 mol%. Strain EN8dT could be clearly differentiated from its phylogenetic neighbours on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore strain EN8dT is considered to represent a novel genus and species, for which the name Sediminibacillus halophilus gen. nov., sp. nov. is proposed. The type strain of Sediminibacillus halophilus is EN8dT (=CCM 7364T =CECT 7148T =CGMCC 1.6199T =DSM 18088T).

Salsuginibacillus kocurii gen. nov., sp. nov., a moderately halophilic bacterium from soda-lake sediment.

A Gram-positive, endospore-forming, alkali-tolerant, moderately halophilic bacterium, designated strain CH9d(T), was isolated from the sediment of Lake Chagannor in the Inner Mongolia Autonomous Region, China. The cells were rod-shaped and motile. Isolate CH9d(T) grew at pH 5.8-10.0 (optimally at pH 8.5), at salinities of 3-20 % (w/v) marine salts (optimally at 10.0 %, w/v) and between 20 and 50 degrees C (optimally at 37 degrees C). The cell wall contained meso-diaminopimelic acid and the major respiratory isoprenoid quinone was MK-7. The predominant cellular fatty acids of strain CH9d(T) were anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(17 : 0) and iso-C(15 : 0) and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unknown phospholipids. The G+C content of the DNA was 44.7 mol%. Strain CH9d(T) exhibited a 16S rRNA gene sequence similarity value of only 91 % with respect to Thalassobacillus devorans DSM 16966(T) and showed values below 91 % with respect to members of the genera Bacillus, Halobacillus and Marinococcus. Strain CH9d(T) could be clearly differentiated from its closest phylogenetic neighbours on the basis of several phenotypic, genotypic and chemotaxonomic features. Therefore, data from the polyphasic study support the placement of strain CH9d(T) in a novel genus and species, for which the name Salsuginibacillus kocurii gen. nov., sp. nov. is proposed. The type strain is CH9d(T) (=CCM 7365(T)=CECT 7154(T)=CGMCC 1.6287(T)=DSM 18087(T)).

Bacillus chagannorensis sp. nov., a moderate halophile from a soda lake in Inner Mongolia, China.

A Gram-positive, moderately halophilic, spore-forming bacterium, designated strain CG-15(T), was isolated from a soda lake, Lake Chagannor, in the Inner Mongolia Autonomous Region, China. The cells were found to be motile short rods with ellipsoidal, terminal and deforming endospores. Strain CG-15(T), a facultatively anaerobic bacterium, grew at pH 5.8-11.0 (optimally at pH 8.5), at 6-40 degrees C (optimally at 37 degrees C) and at salinities of 3-20 % (w/v) total salts (optimally at 7 % w/v). On the basis of the results of 16S rRNA gene sequence analysis, strain CG-15(T) was shown to belong to the genus Bacillus (phylum Firmicutes), showing the greatest phylogenetic similarity with respect to Bacillus saliphilus (96.0 %). The DNA G+C content of the novel isolate was found to be 53.8 mol%. The major cellular fatty acids of strain CG-15(T) were anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0), and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three different unidentified phospholipids. The analysis of the quinones showed that MK-7 was the major menaquinone. The peptidoglycan type was A1gamma, with meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of the data from this polyphasic study, strain CG-15(T) represents a novel species of the genus Bacillus, for which the name Bacillus chagannorensis sp. nov. is proposed. The type strain is CG-15(T) (=CCM 7371(T)=CECT 7153(T)=CGMCC 1.6292(T)=DSM 18086(T)).

Aquisalimonas asiatica gen. nov., sp. nov., a moderately halophilic bacterium isolated from an alkaline, saline lake in Inner Mongolia, China.

Two novel moderately halophilic, Gram-negative rods (strains CG12(T) and CG13) were isolated from Lake Chagannor in Inner Mongolia Autonomous Region, China. They were strictly aerobic and motile. They grew at pH 6.0-10.8 (optimally at pH 7.5-8.5), at 20-50 degrees C (optimally at 37 degrees C) and at salinities of 1-20 % (w/v) total salts (optimally at 7-10 %, w/v). Phylogenetic analysis of the two strains, based on a comparison of their 16S rRNA genes, led to their classification within the class Gammaproteobacteria, the closest recognized type strain being Alkalispirillum mobile DSM 12769(T), with which they were found to share 94.4-94.6 % sequence similarity. On the basis of DNA-DNA hybridization data (showing 100 and 99 % relatedness for each other), the two isolates were found to be members of the same species. The DNA G+C contents of strains CG12(T) and CG13 were found to be 63.6 and 64.0 mol%, respectively. The major cellular fatty acids of strain CG12(T), selected as the representative strain, were C(18 : 1)omega7c, C(16 : 0) and C(12 : 0), and its polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, a phosphoglycolipid and six unidentified phospholipids. On the basis of the polyphasic evidence from this study, strains CG12(T) and CG13 represent a novel genus and species, for which the name Aquisalimonas asiatica gen. nov., sp. nov. is proposed. The type strain of Aquisalimonas asiatica is CG12(T) (=CCM 7368(T)=CECT 7151(T)=CGMCC 1.6291(T)=DSM 18102(T)).

Gracilibacillus orientalis sp. nov., a novel moderately halophilic bacterium isolated from a salt lake in Inner Mongolia, China.

Three Gram-positive, moderately halophilic, spore-forming rods, designated XH-63T, XH-62 and EJ-15, were isolated from two salt lakes located near Xilin Hot and Ejinor, in Inner Mongolia, China. The strains were strictly aerobic and motile, with spherical, terminal and deforming endospores. They grew at pH 5.0-9.0 (optimal growth at pH 7.5), between 4 and 45 degrees C (optimal growth at 37 degrees C) and at salinities of 1-20% (w/v) total salts, growing optimally at 10% (w/v) salts. They had meso-diaminopimelic acid in the cell wall peptidoglycan and DNA G + C contents of 36.1-37.1 mol%. The polar lipid pattern of strain XH-63T, selected as the representative strain, consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and a phospholipid and two amino phospholipids of unknown structure. This strain possessed anteiso-C(15:0) and anteiso-C(17:0) as the major fatty acids (altogether representing 72.5% of total) and MK-7 as the major menaquinone. 16S rRNA gene analysis of the three strains showed that they were within the Gracilibacillus cluster, with highest sequence similarity (95.4-95.8%) with Gracilibacillus dipsosauri. Based on a combination of phenotypic, chemotaxonomic and phylogenetic features, it is proposed that the three isolates represent a novel species of the genus Gracilibacillus, Gracilibacillus orientalis sp. nov. The type strain is strain XH-63T (= CCM 7326T = AS 1.4250T = CECT 7097T).