Gracilibacillus kekensis sp. nov., a moderate halophile isolated from Keke Salt Lake

Intestinal microbiota and metabolome perturbations in ischemic and idiopathic dilated cardiomyopathy

BACKGROUND

Various clinical similarities are present in ischemic (ICM) and idiopathic dilated cardiomyopathy (IDCM), leading to ambiguity on some occasions. Previous studies have reported that intestinal microbiota appeared dysbiosis in ICM, whether implicating in the IDCM remains unclear. The aim of this study was to assess the alterations in intestinal microbiota and fecal metabolites in ICM and IDCM.

METHODS

ICM (n = 20), IDCM (n = 22), and healthy controls (HC, n = 20) were enrolled in this study. Stool samples were collected for 16S rRNA gene sequencing and gas chromatography-mass spectrometry (GC-MS) analysis.

RESULTS

Both ICM and IDCM exhibited reduced alpha diversity and altered microbial community structure compared to HC. At the genus level, nine taxa including Blautia, [Ruminococcus]_torques_group, Christensenellaceae_R-7_group, UCG-002, Corynebacterium, Oceanobacillus, Gracilibacillus, Klebsiella and Citrobacter was specific to ICM, whereas one taxa Alistipes uniquely altered in IDCM. Likewise, these changes were accompanied by significant metabolic differences. Further differential analysis displayed that 18 and 14 specific metabolites uniquely changed in ICM and IDCM, respectively. The heatmap was generated to display the association between genera and metabolites. Receiver operating characteristic curve (ROC) analysis confirmed the predictive value of the distinct microbial-metabolite features in disease status. The results showed that microbial (area under curve, AUC = 0.95) and metabolic signatures (AUC = 0.84) were effective in discriminating ICM from HC. Based on the specific microbial and metabolic features, the patients with IDCM could be separated from HC with an AUC of 0.80 and 0.87, respectively. Furthermore, the gut microbial genus (AUC = 0.88) and metabolite model (AUC = 0.89) were comparable in predicting IDCM from ICM. Especially, the combination of fecal microbial-metabolic features improved the ability to differentiate IDCM from ICM with an AUC of 0.96.

CONCLUSION

Our findings highlighted the alterations of gut microbiota and metabolites in different types of cardiomyopathies, providing insights into the pathophysiological mechanisms of myocardial diseases. Moreover, multi-omics analysis of fecal samples holds promise as a non-invasive tool for distinguishing disease status.

Gracilibacillus salinarum sp. nov. and Gracilibacillus caseinilyticus sp. nov., halotolerant bacteria isolated from a saltern environment

Two aerobic, Gram-stain-positive, spore-forming motile bacterial strains, designated SSPM10-3T and SSWR10-1T, were isolated from salterns in Jeollanam province of South Korea. Both strains were halotolerant and grew well in 5 % NaCl but not in 20 and 25% NaCl, respectively. Optimal growth was observed with 5 % NaCl, at 30 °C and at pH 7.0-8.0. On the basis of the results of phylogenetic analysis using 16S rRNA gene sequence, both the strains were placed within the genus Gracilibacillus with Gracilibacillus massiliensis (98.65 % similarity) as their nearest neighbour. Menaquinone-7 (MK-7) (97 %) was the major isoprenoid quinone in both strains and major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. Orthologous average nucleotide identity with usearch (OrthoANIu) and digital DNA-DNA hybridisation (dDDH) percentage comparison indicated that SSPM10-3T and SSWR10-1T exhibited highest similarity with G. massiliensis Awa-1T at 74.27 % and 21.0 and 74.23 % and 20.0 %, respectively. The DNA G+C contents of the strains were 39.1 % (SSPM10-3T) and 38.5 % (SSWR10-1T). Members of the genus Gracilibacillus, both strains were distinct from each other with respect to their ability to produce urease, β-glucosidase, assimilation of inulin and methyl-α-d-glucopyranoside and degradation of casein. Compared with each other, ANI and d4 dDDH calculations were only 88.2 % and 36.3 %, well below the cut-off values for species delineation for each index. On the basis of their phenotypic, physiological, biochemical and phylogenetic characteristics,SSPM10-3T and SSWR10-1T represent distinct novel species for which names Gracilibacillus salinarum SSPM10-3T and Gracilibacillus caseinilyticus SSWR10-1T are proposed. The type strains are SSPM10-3T (=KACC 21933T =NBRC 115502T) and SSWR10-1T (=KACC 21934T =NBRC 115503T).

Gracilibacillus suaedae sp. nov., an indole acetic acid-producing endophyte isolated from a root of Suaeda salsa

A Gram-stain-positive, facultatively anaerobic, spore-forming, motile with unipolar biflagella, rod-shaped, indole acetic acid-producing bacterium, named LD4P30^T, was isolated from a root of Suaeda salsa collected in Inner Mongolia, northern China. Strain LD4P30^T grew at pH 6.0-11.0 (optimum, pH 7.0), 10-40 °C (35 °C) and in the presence of 1-15% (w/v) NaCl (5%). The strain was positive for oxidase and negative for catalase. The major cellular fatty acids of strain LD4P30^T were iso-C_15:0, C_15:1 ω5c and anteiso-C_15:0; the major polar lipids were diphosphatidylglycerol and phosphatidylglycerol; and menaquinone-7 was the only respiratory quinone. The genomic DNA G+C content was 36.7 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain LD4P30^T clustered with Gracilibacillus thailandensis TP2-8^T, Gracilibacillus saliphilus YIM 91119^T and Gracilibacillus lacisalsi BH312^T, and showed 99.0, 98.9, 98.0 and <97.7% 16S rRNA gene similarity to G. thailandensis TP2-8^T, G. saliphilus YIM 91119^T, G. lacisalsi BH312^T and all other current type strains, respectively. The digital DNA-DNA hybridization and average nucleotide identity based on blast values between strain LD4P30^T and G. saliphilus YIM 91119^T, G. thailandensis TP2-8^T and G. lacisalsi BH312^T were 44.9, 44.7 and 44.4%, and 91.1, 91.0 and 90.8%, respectively. Based on its phenotypic, physiological and phylogenetic characteristics, strain LD4P30^T represents a novel species, for which the name Gracilibacillus suaedae is proposed. The type strain is LD4P30^T (=CGMCC 1.17697^T=KCTC 82375^T).

Characterization of β-galactosidase and α-galactosidase activities from the halophilic bacterium Gracilibacillus dipsosauri

Purpose

Gracilibacillus dipsosauri strain DD1 is a salt-tolerant Gram-positive bacterium that can hydrolyze the synthetic substrates o-nitrophenyl-β-d-galactopyranoside (β-ONP-galactose) and p-nitrophenyl-α-d-galactopyranoside (α-PNP-galactose). The goals of this project were to characterize the enzymes responsible for these activities and to identify the genes encoding them.

Methods

G. dipsosauri strain DD1 was grown in tryptic soy broth containing various carbohydrates at 37 °C with aeration. Enzyme activities in cell extracts and whole cells were measured colorimetrically by hydrolysis of synthetic substrates containing nitrophenyl moieties. Two enzymes with β-galactosidase activity and one with α-galactosidase activity were partially purified by ammonium sulfate fractionation, ion-exchange chromatography, and gel-filtration chromatography from G. dipsosauri. Coomassie Blue-stained bands corresponding to each activity were excised from nondenaturing polyacrylamide gels and subjected to peptide sequencing after trypsin digestion and HPLC/MS analysis.

Result

Formation of β-galactosidase and α-galactosidase activities was repressed by d-glucose and not induced by lactose or d-melibiose. β-Galactosidase I had hydrolytic and transgalactosylation activity with lactose as the substrate but β-galactosidase II showed no activity towards lactose. The α-galactosidase had hydrolytic and transgalactosylation activity with d-melibiose but not with d-raffinose. β-Galactosidase I had a lower Km with β-ONP-galactose as the substrate (0.693 mmol l−1) than β-galactosidase II (1.662 mmol l−1), was active at more alkaline pH, and was inhibited by the product d-galactose. β-Galactosidase II was active at more acidic pH, was partially inhibited by ammonium salts, and showed higher activity with α-PNP-arabinose as a substrate. The α-galactosidase had a low Km with α-PNP-galactose as the substrate (0.338 mmol l−1), a pH optimum of about 7, and was inhibited by chloride-containing salts. β-Galactosidase I activity was found to be due to the protein A0A317L6F0 (encoded by gene DLJ74_04930), β-galactosidase II activity to the protein A0A317KZG3 (encoded by gene DLJ74_12640), and the α-galactosidase activity to the protein A0A317KU47 (encoded by gene DLJ74_17745).

Conclusions

G. dipsosauri forms three intracellular enzymes with different physiological properties which are responsible for the hydrolysis of β-ONP-galactose and α-PNP-galactose. BLAST analysis indicated that similar β-galactosidases may be formed by G. ureilyticus, G. orientalis, and G. kekensis and similar α-galactosidases by these bacteria and G. halophilus.

Description of Gracilibacillus phocaeensis sp. nov., a new halophilic bacterium isolated from Senegalian human stool

Using the taxonogenomics method, we describe Gracilibacillus phocaeensis strain Marseille-P3801, a new species previously isolated from a salty stool of a 20-year-old man from N'Diop, Senegal. It is a Gram-positive, aerobic and motile bacillus. The major fatty acids are C15:0-anteiso (59%), C16:0 (16%) and C17:0-anteiso (11%). Strain Marseille-P3801 exhibits a 98.45% sequence similarity with Gracilibacillus thailandensis strain TP2-8, the phylogenetically closest species. Its genome is 4.66 Mb with 39.6 mol% G + C content.

Gracilibacillus oryzae sp. nov., isolated from rice seeds

A Gram-stain-positive, facultatively anaerobic, endospore-forming bacterium, designated strain TD8^T, was isolated from surface-sterilized rice seeds (Oryza sativa L.). Phylogenetic analysis of the 16S rRNA gene indicated that strain TD8^T should be placed within the genus Gracilibacillus (95.2-99.0 % sequence similarity); it exhibited highest similarities to Gracilibacillus ureilyticus CGMCC 1.7727^T (99.0 %), 'Gracilibacillus xinjiangensis' CGMCC 1.12449^T (98.9 %) and Gracilibacillus dipsosauri CGMCC 1.3642^T (97.5 %). Chemotaxonomic analysis showed that menaquinone-7 (MK-7) was the major isoprenoid quinone. Diphosphatidylglycerol, phosphatidylglycerol and one unidentified phospholipid were the major cellular polar lipids, and the major fatty acids were anteiso-C_15 : 0, anteiso-C_17 : 0, iso-C_15 : 0, C_16 : 0 and iso-C_16 : 0, which supported the allocation of the strain to the genus Gracilibacillus. The digital DNA-DNA hybridization value between strain TD8^T and Gracilibacillus ureilyticus CGMCC 1.7727^T was lower than 70 % (22.60 %), and the average nucleotide identity score was 79.54±5.09 %, suggesting that strain TD8^T represented a novel species in the genus Gracilibacillus. The genomic DNA G+C content was 37.5 %. Based on physiological and biochemical characteristics and genotypic data, strain TD8^T represents a novel species of the genus Gracilibacillus, for which the name Gracilibacillus oryzae sp. nov. is proposed. The type strain is TD8^T (=ACCC 61556^T=CICC 24889^T=JCM 33537^T).

Genomic sequencing of Gracilibacillus dipsosauri reveals key properties of a salt-tolerant α-amylase

Gracilibacillus dipsosauri is a moderately-halophilic Gram-positive bacterium which forms an extracellular α-amylase that is induced by starch, repressed by D-glucose, and active in 2.0 M KCl. Previous studies showed that while enzyme activity could be measured with the synthetic substrate 2-chloro-4-nitrophenyl-α-D-maltotrioside (CNPG3), other assays were inconsistent and the protein showed aberrant mobility during nondenaturing gel electrophoresis. To clarify the properties of this enzyme, the genome of G. dipsosauri was sequenced and was found to be 4.19 Mb in size with an overall G+C content of 36.9%. A gene encoding an α-amylase composed of 691 amino acids was identified. The protein was a member of the glycosyl hydrolase 13 family, which had a molecular mass of 77,396 daltons and a pI of 4.39 due to an unusually large number of aspartate and glutamate residues (95/691 or 13.7%). BLAST analysis of the amino acid sequence revealed significant matches to other proteins with cyclodextrin glycosyltransferase activity. Partial purification of the protein from G. dipsosauri showed that fractions catalyzing the hydrolysis of CNPG3 and p-nitrophenyl-D-maltoheptoside also catalyzed the formation of β-cyclodextrin but not α-cyclodextrin or γ-cyclodextrin. Formation of β-cyclodextrin was not stimulated by high salt concentrations but did occur with rice, potato, wheat, and corn starches and amylopectin. These studies explain the unusual features of the α-amylase from G. dipsosauri and indicate it should be classified as EC 2.4.1.19. The availability of the complete genomic sequence of G. dipsosauri will provide the basis for studies on other enzymes from this halophile which may be useful for biotechnology.

Genome sequence and description of Gracilibacillus timonensis sp. nov. strain Marseille-P2481T , a moderate halophilic bacterium isolated from the human gut microflora

Microbial culturomics represents an ongoing revolution in the characterization of the human gut microbiota. By using three culture media containing high salt concentrations (10, 15, and 20% [w/v] NaCl), we attempted an exhaustive exploration of the halophilic microbial diversity of the human gut and isolated strain Marseille‐P2481 (= CSUR P2481 =  DSM 103076), a new moderately halophilic bacterium. This bacterium is a Gram‐positive, strictly aerobic, spore‐forming rod that is motile by use of a flagellum and exhibits catalase, but not oxidase activity. Strain Marseille‐P2481 was cultivated in media containing up to 20% (w/v) NaCl, with optimal growth being obtained at 37°C, pH 7.0–8.0, and 7.5% [w/v] NaCl). The major fatty acids were 12‐methyl‐tetradecanoic acid and hexadecanoic acid. Its draft genome is 4,548,390 bp long, composed of 11 scaffolds, with a G+C content of 39.8%. It contains 4,335 predicted genes (4,266 protein coding including 89 pseudogenes and 69 RNA genes). Strain Marseille‐P2481 showed 96.57% 16S rRNA sequence similarity with Gracilibacillus alcaliphilus strain SG103^T, the phylogenetically closest species with standing in nomenclature. On the basis of its specific features, strain Marseille‐P2481^T was classified as type strain of a new species within the genus Gracilibacillus for which the name Gracilibacillus timonensis sp. nov. is formally proposed.

Microbial community structure and diversity within hypersaline Keke Salt Lake environments

Keke Salt Lake is located in the Qaidamu Basin of China. It is a unique magnesium sulfate-subtype hypersaline lake that exhibits a halite domain ecosystem, yet its microbial diversity has remained unstudied. Here, the microbial community structure and diversity was investigated via high-throughput sequencing of the V3-V5 regions of 16S rRNA genes. A high diversity of operational taxonomic units was detected for Bacteria and Archaea (734 and 747, respectively), comprising 21 phyla, 43 classes, and 201 genera of Bacteria and 4 phyla, 4 classes, and 39 genera of Archaea. Salt-saturated samples were dominated by the bacterial genera Bacillus (51.52%-58.35% relative abundance), Lactococcus (9.52%-10.51%), and Oceanobacillus (8.82%-9.88%) within the Firmicutes phylum (74.81%-80.99%), contrasting with other hypersaline lakes. The dominant Archaea belonged to the Halobacteriaceae family, and in particular, the genera (with an abundance of >10% of communities) Halonotius, Halorubellus, Halapricum, Halorubrum, and Natronomonas. Additionally, we report the presence of Nanohaloarchaeota and Woesearchaeota in Qinghai-Tibet Plateau lakes, which has not been previously documented. Total salinity (especially Mg²⁺, Cl^-, Na⁺, and K⁺) mostly correlated with taxonomic distribution across samples. These results expand our understanding of microbial resource utilization within hypersaline lakes and the potential adaptations of dominant microorganisms that allow them to inhabit such environments.

Two Distinct α-l-Arabinofuranosidases in Caldicellulosiruptor Species Drive Degradation of Arabinose-Based Polysaccharides

Species in the extremely thermophilic genus Caldicellulosiruptor can degrade unpretreated plant biomass through the action of multimodular glycoside hydrolases. To date, most focus with these bacteria has been on hydrolysis of glucans and xylans, while the biodegradation mechanism for arabinose-based polysaccharides remains unclear. Here, putative α-l-arabinofuranosidases (AbFs) were identified in Caldicellulosiruptor species by homology to less-thermophilic versions of these enzymes. From this screen, an extracellular XynF was determined to be a key factor in hydrolyzing α-1,2-, α-1,3-, and α-1,5-l-arabinofuranosyl residues of arabinose-based polysaccharides. Combined with a GH11 xylanase (XynA), XynF increased arabinoxylan hydrolysis more than 6-fold compared to the level seen with XynA alone, likely the result of XynF removing arabinofuranosyl side chains to generate linear xylans that were readily degraded. A second AbF, the intracellular AbF51, preferentially cleaved the α-1,5-l-arabinofuranosyl glycoside bonds within sugar beet arabinan. β-Xylosidases, such as GH39 Xyl39B, facilitated the hydrolysis of arabinofuranosyl residues at the nonreducing terminus of the arabinose-branched xylo-oligosaccharides by AbF51. These results demonstrate the separate but complementary contributions of extracellular XynF and cytosolic AbF51 in processing the bioconversion of arabinose-containing oligosaccharides to fermentable monosaccharides.IMPORTANCE Degradation of hemicellulose, due to its complex chemical structure, presents a major challenge during bioconversion of lignocellulosic biomass to biobased fuels and chemicals. Degradation of arabinose-containing polysaccharides, in particular, can be a key bottleneck in this process. Among Caldicellulosiruptor species, the multimodular arabinofuranosidase XynF is present in only selected members of this genus. This enzyme exhibited high hydrolysis activity, broad specificity, and strong synergism with other hemicellulases acting on arabino-polysaccharides. An intracellular arabinofuranosidase, AbF51, occurs in all Caldicellulosiruptor species and, in conjunction with xylosidases, processes the bioconversion of arabinose-branched oligosaccharides to fermentable monosaccharides. Taken together, the data suggest that plant biomass degradation in Caldicellulosiruptor species involves extracellular XynF that acts synergistically with other hemicellulases to digest arabino-polysaccharides that are subsequently transported and degraded further by intracellular AbF51 to produce short-chain arabino sugars.

Microbial culturomics unravels the halophilic microbiota repertoire of table salt: description of Gracilibacillus massiliensis sp. nov

Background

Microbial culturomics represents an ongoing revolution in the characterization of environmental and human microbiome.

Methods

By using three media containing high salt concentration (100, 150, and 200 g/L), the halophilic microbial culturome of a commercial table salt was determined.

Results

Eighteen species belonging to the Terrabacteria group were isolated including eight moderate halophilic and 10 halotolerant bacteria. Gracilibacillus massiliensis sp. nov., type strain Awa-1^T (=CSUR P1441=DSM 29726), is a moderately halophilic gram-positive, non-spore-forming rod, and is motile by using a flagellum. Strain Awa-1^T shows catalase activity but no oxidase activity. It is not only an aerobic bacterium but also able to grow in anaerobic and microaerophilic atmospheres. The draft genome of G. massiliensis is 4,207,226 bp long, composed of 13 scaffolds with 36.05% of G+C content. It contains 3,908 genes (3,839 protein-coding and 69 RNA genes). At least 1,983 (52%) orthologous proteins were not shared with the closest phylogenetic species. Hundred twenty-six genes (3.3%) were identified as ORFans.

Conclusions

Microbial culturomics can dramatically improve the characterization of the food and environmental microbiota repertoire, deciphering new bacterial species and new genes. Further studies will clarify the geographic specificity and the putative role of these new microbes and their related functional genetic content in environment, health, and disease.

Gracilibacillus kimchii sp. nov., a halophilic bacterium isolated from kimchi

A novel halophilic bacterium, strain K7(T), was isolated from kimchi, a traditional Korean fermented food. The strain is Gram-positive, motile, and produces terminal endospores. The isolate is facultative aerobic and grows at salinities of 0.0-25.0% (w/v) NaCl (optimum 10-15% NaCl), pH 5.5-8.5 (optimum pH 7.0-7.5), and 15-42°C (optimum 37°C). The predominant isoprenoid quinone in the strain is menaquinone-7 and the peptidoglycan of the strain is meso-diaminopimelic acid. The major fatty acids of the strain are anteisio-C15:0, iso-C15:0, and, C16:0 (other components were < 10.0%), while the major polar lipids are diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, and three unidentified lipids. A phylogenetic analysis of 16S rRNA gene sequence similarity showed that the isolated strain was a cluster of the genus Gracilibacillus. High levels of gene sequence similarity were observed between strain K7(T) and Gracilibacillus orientalis XH-63(T) (96.5%), and between the present strain and Gracilibacillus xinjiangensis (96.5%). The DNA G+C content of this strain is 37.7 mol%. Based on these findings, strain K7(T) is proposed as a novel species: Gracilibacillus kimchii sp. nov. The type strain is K7(T) (KACC 18669(T); JCM 31344(T)).

Gracilibacillus alcaliphilus sp. nov., a facultative alkaliphile isolated from indigo fermentation liquor for dyeing

A facultatively alkaliphilic, lactic-acid-producing and halophilic strain, designated SG103T, was isolated from a fermented Polygonum indigo (Polygonum tinctorium Lour.) liquor sample for dyeing prepared in a laboratory. 16S rRNA gene sequence phylogeny suggested that SG103T is a member of the genus Gracilibacillus with the closest relatives being ‘Gracilibacillus xinjiangensis’ J2 (similarity: 97.06 %), Gracilibacillus thailandensis TP2-8T (97.06 %) and Gracilibacillus halotolerans NNT (96.87 %). Cells of the isolate stained Gram-positive and were facultatively anaerobic straight rods that were motile by peritrichous flagella. The strain grew at temperatures between 13 and 48 °C with the optimum at 39 °C. It grew in the range pH 7–10 with the optimum at pH 9. The isoprenoid quinone detected was menaquinone-7 (MK-7) and the DNA G+C content was 41.3 mol%. The whole-cell fatty acid profile mainly (>10 %) consisted of iso-C15 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. Unlike other reported species of the genus Gracilibacillus , the strain lacked diphosphatidylglycerol as a major polar lipid. DNA–DNA hybridization experiments with strains exhibiting greater than 96.87 % 16S rRNA gene sequence similarity, ‘G. xinjiangensis’ J2, G. thailandensis TP2-8T and G. halotolerans NNT, revealed 2±4 %, 4±9 % and 3±2 % relatedness, respectively. On the basis of the differences in phenotypic and chemotaxonomic characteristics, and the results of phylogenetic analyses based on 16S rRNA gene sequences and DNA–DNA relatedness data from reported species of the genus Gracilibacillus , strain SG103T merits classification as a members of a novel species, for which the name Gracilibacillus alcaliphilus sp. nov. is proposed. The type strain is SG103T ( = JCM 17253T = NCIMB 14683T).

Gracilibacillus marinus sp. nov., isolated from the northern South China Sea

Two gram-positive, aerobic, spore-forming, rod-shaped bacteria, designated HB09003(T) and HB12160, were isolated from seawater and sediment in the northern South China Sea, respectively. Cells were found to be motile by means of peritrichous flagella. The strains were found to grow with 0-15 % (w/v) NaCl, at 10-45 °C and pH 5.0-10.7, with an optimum of 3 % NaCl, 28 °C and pH 8.5, respectively. The predominant isoprenoid quinone of strain HB09003(T), selected as the representative strain, was identified as MK-7. This strain was found to possess anteiso-C15:0, iso-C15:0, anteiso-C17:0 and C16:0 as the major fatty acids. The G+C contents of strain HB09003(T) and HB12160 were determined to be 34.1 and 34.3 mol%, respectively. Analysis of the 16S rRNA gene sequences of the two strains showed an affiliation with the genus Gracilibacillus, with Gracilibacillus kekensis CGMCC 1.10681(T) (similarity of 97.4, 98.0 %, respectively) and Gracilibacillus ureilyticus CGMCC 1.7727(T) (similarity of 97.1, 97.8 %, respectively) as their closest relatives. The DNA-DNA hybridization values between strain HB09003(T) and the two type strains were 42.2 and 54.1 %, respectively. On the basis of phenotypic and genotypic data, strain HB09003(T) and HB12160 are proposed to represent a novel species of the genus Gracilibacillus, for which the name Gracilibacillus marinus sp. nov. is proposed. The type strain is HB09003(T) (=CGMCC 1.10343(T) = DSM 23372(T)).

Gracilibacillus xinjiangensis sp. nov., a new member of the genus Gracilibacillus isolated from Xinjiang region, China

A Gram-positive, endospore-forming, rod-shaped bacterium, designated isolate J2(T) was isolated from a soil sample from Xinjiang Uyghur Autonomous Region, China. The isolate was observed to grow at 16-46 °C and pH 6.5-8.0. Chemotaxonomic analysis showed menaquinone-7 (MK-7) to be the major isoprenoid quinone; diphosphatidylglycerol, phosphatidylglycerol, one aminophospholipid, two phosphoglycolipids and one glycolipid as the major cellular polar lipids; and anteiso-C15:0, iso-C15:0, anteiso-C17:0 and C16:0 as the major fatty acids. Comparative analyses of the 16S rRNA gene sequence showed that strain J2(T) is most closely related to Gracilibacillus ureilyticus (with 98.8 % similarity), Gracilibacillus dipsosauri (97.2 %), Gracilibacillus quinghaiensis (97.1 %) and Gracilibacillus thailandensis (97.0 %). The DNA-DNA reassociation values between strain J2(T) and G. ureilyticus MF38(T), G. dipsosauri DD1(T), G. quinghaiensis YIM-C229(T) and G. thailandensis TP2-8(T) were 29.8 ± 3.7, 23.0 ± 3.5, 15.8 ± 4.9 and 15.9 ± 5.0 %, respectively. The genomic DNA G+C content of strain J2(T) was determined to be 36.5 mol%. Based on these data, strain J2(T) is considered as a novel species of the genus Gracilibacillus, for which the name Gracilibacillus xinjiangensis sp. nov. is proposed. The type species is J2(T) (= CGMCC 1.12449(T) = JCM 18859(T)).