Genome-based reclassification of Bacillus okuhidensis as a later heterotypic synonym of Bacillus halodurans.

The present study was carried out to clarify the taxonomic relationship between two closely related Bacillus species, Bacillus okuhidensis Li et al. 2002 and Bacillus halodurans (ex Boyer 1973) Nielsen et al. 1995. The maximum-likelihood tree based on the 16S rRNA gene sequence and the phylogenomic tree based on concatenation of 16 protein-marker genes showed that these species were similar. Average nucleotide identity (ANIm 99.25 %, ANIb 98.2 %) and digital DNA-DNA hybridization values (93.5 %) between B. okuhidensis DSM 13666T and B. halodurans DSM 497T were greater than the threshold values for bacterial species delineation, indicating that they belong to the same species. Therefore, B. okuhidensis Li et al. 2002 should be reclassified as a later heterotypic synonym of B. halodurans (ex Boyer 1973) Nielsen et al. 1995.

Genome-based reclassification of Bacillus plakortidis Borchert et al. 2007 and Bacillus lehensis Ghosh et al. 2007 as a later heterotypic synonym of Bacillus oshimensis Yumoto et al. 2005; Bacillus rhizosphaerae Madhaiyan et al. 2011 as a later heterotypic synonym of Bacillus clausii Nielsen et al. 1995.

In the present study, phylogenetic and genome-based comparison was carried out to clarify the taxonomic positions of alkaliphilic Bacillus species, Bacillus plakortidis, Bacillus lehensis, Bacillus oshimensis, Bacillus rhizosphaerae and Bacillus clausii. Phylogenetic trees based on 16S rRNA gene sequences and concatenated protein marker genes were constructed. Average nucleotide identity (ANI) values were calculated to compare genetic relatedness. In phylogenetic trees, B. plakortidis DSM 19153T, B. lehensis DSM 19099T, and B. oshimensis DSM 18940T; B. rhizosphaerae DSM 21911T and B. clausii DSM 8716T clade together. The average nucleotide identity (ANI) values between B. oshimensis DSM 18940T, B. plakortidis DSM 19153T and B. lehensis DSM 19099T ranged from 98.7-98.8%, while the ANI values between B. rhizosphaerae DSM 21911T and B. clausii DSM 8716T were 95.2-95.5%. The ANI values were higher than the recognized threshold value for bacterial species delineation. Based on phylogenetic and genome comparison we propose reclassification of B. plakortidis and B. lehensis as a later heterotypic synonym of B. oshimensis; B. rhizosphaerae as a later heterotypic synonym of B. clausii.

Bacillus xiapuensis sp. nov., isolated from marine sediment.

A rod-shaped, endospore-forming, aerobic bacterium, designated FJAT-46582T, was isolated from a sediment sample of the coastal region in Xiapu County, Fujian Province in China. Growth was observed at 10-30 °C (optimum, 25 °C), in 0-7.0 % NaCl (0 %) and at pH 6.0-11.0 (pH 8.0), respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the isoprenoid quinone was MK-7. The main fatty acids were anteiso-C17 : 0 (26.5 %), anteiso-C15 : 0 (19.6 %), iso-C15 : 0 (14.4 %) and C16 : 0 (10.5 %). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidyl ethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain FJAT-46582T with the genus Bacillus, and showed the highest sequence similarity to Bacillus thermotolerans SGZ-8T (97.6 %) and Bacillus ectoinformans (97.1 %). The average nucleotide identity and in silico DNA-DNA hybridization values between strain FJAT-46582T and the most closely related species were 72.3 and 22.9 %, respectively, which were much lower than the thresholds commonly used to define species (96 and 70 %, respectively) indicating that it belonged to a different taxon. The DNA G+C content was 44.2 mol%. The phenotypic characters and taxono-genomics study revealed that strain FJAT-46582T represents a novel Bacillus species, for which the name Bacillus xiapuensis sp. nov. is proposed. The type strain is FJAT-46582T (=JCM 33155=CCTCC AB 2017047T).

Bacillus populi sp. nov. isolated from Populus euphratica rhizosphere soil of the Taklamakan desert.

A rod-shaped, endospore-forming, aerobic bacterium, designated FJAT-45347T, was isolated from rhizosphere soil collected from the Taklamakan desert in Xinjiang (PR China). Growth was observed at 15-35 °C (optimum 25 °C), in 0 % and 20.0 % NaCl (optimum 8.0 %) and at pH 7.5-12.0 (optimum 8.0), respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the isoprenoid quinone was MK-7. The main fatty acids were iso-C15 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences affiliated FJAT-45347T to the genus Bacillus, and it showed the highest sequence similarities to Bacillus clarkii DSM 8720T (96.1 %). The average nucleotide identity and in silico DNA-DNA hybridization values between FJAT-45347T and the most closely related species were 68.5 and 26.2 %, respectively, which were lower than the thresholds commonly used to define species (96 and 70 %, respectively), indicating that it represented a member of a different taxon. The DNA G+C content was 40.6 mol%. The phenotypic characters and taxono-genomics study revealed that FJAT-45347T represents a novel species of the genus Bacillus, for which the name Bacilluspopuli sp. nov. is proposed. The type strain is FJAT-45347T (=DSM 104632T=CCTCC AB 2016257T).

Bacillus wudalianchiensis sp. nov., isolated from grass soils of the Wudalianchi scenic area.

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium, designated FJAT-27215T, was isolated from grass soil collected from Wudalianchi in the Heilongjiang Province of China. Growth was observed at 10-60 °C (optimum 30 °C), in 0 and 3.0 % NaCl (optimum 0 %) and at pH 5.0-10.0 (optimum 7.0), respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the isoprenoid quinone was MK7. The main fatty acids were iso-C15 : 0, anteiso-C15 : 0, anteiso-C17 : 0, and iso-C16 : 0. The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidyl ethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain FJAT-27215T to the genus Bacillus. Strain FJAT-27215T showed high sequence similarities to Bacillus encimensis SGD-V-25T (98.6 %), Bacillus badius NBRC 15713T (98.6 %), Domibacillus indicus SD111T (96.9 %) and Bacillus thermotolerans SgZ-8T (96.5 %). The average nucleotide identity values between strain FJAT-27215T and the type strains of closely related species were much lower than the 96 % threshold value for delineation of genomic prokaryotic species. The in silico DNA-DNA hybridization values between strain FJAT-27215T and the most closely related strain B. encimensis SGD-V-25T showed a similarity of 22.4 % and lower than 70 %, indicating that they belong to different taxa. The phenotypic characters and taxono-genomics study revealed that strain FJAT-27215T represents a novel Bacillus species, for which the name Bacillus wudalianchiensis sp. nov. is proposed. The type strain is FJAT-27215T (=CCTCC AB 2015266T=DSM 100757T).

Bacillus praedii sp. nov., isolated from purplish paddy soil.

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium, designated strain FJAT-25547T, was isolated from the purplish paddy soil collected from Linshan Township, Yanting Prefecture of Sichuan Province in PR China (31° 16' N 105° 27' E). Growth was achieved aerobically at temperatures between 15 and 40 °C (optimum 30 °C), with between 0 and 10.0 % NaCl (w/v) (optimum 4 %) and in the range of pH 5.0-12.0 (optimum pH 9.0). The cell-wall peptidoglycan contained meso-diaminopimelic acid, and the main isoprenoid quinone was MK-7. The major fatty acids were iso-C15 : 0 (55.4 %), anteiso-C15 : 0 (22.2 %), iso-C16 : 0 (5.1 %) and iso-C14 : 0 (6.5 %). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain FJAT-25547T was a member of the genus Bacillus and was most closely related to Bacillus horneckiae DSM 23495T (97.7 % similarity), Bacillus eiseniae A1-2T (97.5 %), Bacillus mesophilum IITR-54T (97.2 %) and Bacillus kochii WCC 4582T (97.0 %). The average nucleotide identity value between strain FJAT-25547T and the type strain of the most closely related species, B. horneckiae DSM 23495T, was 77.7 %, less than the proposed cut-off value of 96.0 % for differentiating species within the genus. The in silico DNA-DNA hybridization value of strain FJAT-25547T with the most closely related species was 22.7 %, <70 %, again indicating they belong to different taxa. The DNA G+C content of strain FJAT-25547T was 39.1 mol%. This taxono-genomics study revealed that strain FJAT-25547T represents a novel species of the genus Bacillus for which the name Bacillus praedii sp. nov. (type strain FJAT-25547T=CCTCC AB 2015208T=DSM 101002T) is proposed.

Paenibacillus solani sp. nov., isolated from potato rhizosphere soil.

A novel Gram-stain-positive, endospore-forming bacterium, designated FJAT-22460T, was isolated from a soil sample of a potato field in Xinjiang Autonomous Region, China. Cells were rods that were catalase-positive and motile by peritrichous flagella. The strain was found to grow at temperatures ranging from 10 to 40 °C (optimum 30 °C) and at pH 5.0-12.0 (optimum pH 7) with 0-5 % (w/v) NaCl (optimum 0 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FJAT-22460T belonged to the genus Paenibacillus and exhibited 16S rRNA gene sequence similarities of 97.3, 97.2, 97.2 and 97.0 % with Paenibacillus glucanolyticus DSM 5162T, Paenibacillus lautus DSM 3035T, Paenibacillus lactis MB 1871T and Paenibacillus chibensis JCM 9905T, respectively. DNA-DNA relatedness of strain FJAT-22460T with Paenibacillus glucanolyticusDSM 5162T and Paenibacillus lautus DSM 3035T was 62.6 % and 33.3 %, respectively, lower than the 70 % accepted for species delineation. The menaquinone was identified as MK-7. The major fatty acids detected were anteiso-C15 : 0 (51.4 %), iso-C15 : 0 (5.3 %), C16 : 0 (12.1 %), iso-C16 : 0 (10.7 %) and anteiso-C17 : 0 (6.9 %). The DNA G+C content was determined to be 50.9 mol%. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that isolate FJAT-22460T represents a novel species within the genus Paenibacillus, for which the name Paenibacillus solani sp. nov. is proposed. The type strain is FJAT-22460T (=DSM 100999T=CCTCC AB 2015207T).

Bacillus solani sp. nov., isolated from rhizosphere soil of a potato field.

A novel Gram-stain-positive, endospore-forming bacterium, designated strain FJAT-18043T, was isolated from a soil sample of a potato field in Xinjiang Autonomous Region, China. Cells were rods that were catalase-positive and motile by peritrichous flagella. The strain grew at 20-45 °C (optimum 35 °C), at pH 6.0-10.0 (optimum pH 9) and with 0-10 % (w/v) NaCl (optimum 0 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FJAT-18043T belonged to the genus Bacillus and exhibited similarities of 97.7, 97.6, 97.2 and 97.2 % with Bacillus eiseniae A1-2T, Bacillus horneckiae DSM 23495T, Bacillus gottheilii WCC 4585T and Bacillus purgationiresistens DS22T, respectively. DNA-DNA relatedness between strain FJAT-18043T and B. eiseniae A1-2 T was lower than 70 % (36.1 %). The menaquinone was identified as MK-7 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids detected were anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0, C16 : 0 and iso-C14 : 0. The DNA G+C content was 48.8 mol%. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that isolate FJAT-18043T represents a novel species within the genus Bacillus, for which the name Bacillus solani sp. nov. is proposed. The type strain is FJAT-18043T ( = DSM 29501T = CCTCC AB 2014277T).

Bacillus wuyishanensis sp. nov., isolated from rhizosphere soil of a medical plant, Prunella vulgaris.

A Gram-staining-positive, rod-shaped, endospore-forming, aerobic bacterium (FJAT-17212(T)) was isolated from the rhizosphere soil of a medical plant, Prunella vulgaris (common selfheal), on the Wuyishan mountain of China. Isolate FJAT-17212(T) grew at 10-50 °C (optimum 30 °C), pH 5-11 (optimum pH 7) and with 0-6% (w/v) NaCl (optimum 2%). Phylogenetic analyses based on 16S rRNA gene sequences showed that isolate FJAT-17212(T) was a member of the genus Bacillus and was most closely related to Bacillus galactosidilyticus DSM 15595(T) (97.3%). DNA-DNA relatedness between isolate FJAT-17212(T) and B. galactosidilyticus DSM 15595(T) was low (35.2% ± 2.3). The diagnostic diamino acid of the peptidoglycan of isolate FJAT-17212(T) was meso-diaminopimelic acid and the predominant isoprenoid quinone was MK-7 (80.8%). The major cellular fatty acids were iso-C15 : 0 (35.7%), anteiso-C15 : 0 (29.8%), iso-C14 : 0 (9.9%) and iso-C16 : 0 (9.9%) and the DNA G+C content was 39.8 mol%. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that isolate FJAT-17212(T) represents a novel species within the genus Bacillus, for which the name Bacillus wuyishanensis sp. nov. is proposed. The type strain is FJAT-17212(T) ( = DSM 27848(T) = CGMCC 1.12709(T)).

Bacillus taiwanensis sp. nov., isolated from a soil sample from Taiwan.

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium (FJAT-14571(T)) was isolated from a soil sample in Taiwan. Strain FJAT-14571(T) grew at 20-40 °C (optimum 35 °C), pH 6-10 (optimum pH 8) and 0-2% (w/v) NaCl (optimum 0%). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain FJAT-14571(T) was a member of the genus Bacillus and was most closely related to Bacillus oceanisediminis DSM 24771(T) (96.2%). DNA-DNA relatedness between strain FJAT-14571(T) and B. oceanisediminis DSM 24771(T) was low (32.0% ± 0.88%). The diagnostic diamino acid of the peptidoglycan of strain FJAT-14571(T) was meso-diaminopimelic acid and the predominant menaquinone was MK-7 (96.6%). The major cellular fatty acids were iso-C15 : 0 (46.4%), anteiso-C15 : 0 (7.6%), iso-C17 : 0 (8.2%) and iso-C16 : 0 (10.0 %) and the DNA G+C content was 40.8 mol%. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that strain FJAT-14571(T) represents a novel species within the genus Bacillus, for which the name Bacillus taiwanensis sp. nov. is proposed. The type strain is FJAT-14571(T) ( = DSM 27845(T) = CGMCC1.1 2698(T)).

Bacillus cihuensis sp. nov., isolated from rhizosphere soil of a plant in the Cihu area of Taiwan.

A Gram-positive, moderately halotolerant, rod-shaped, spore forming bacterium, designated strain FJAT-14515(T) was isolated from a soil sample in Cihu area, Taoyuan County, Taiwan. The strain grew at 10-35 °C (optimum at 30 °C), pH 5.7-9.0 (optimum at pH 7.0) and at salinities of 0-5 % (w/v) NaCl (optimum at 1 % w/v). The diagnostic diamino acid of the peptidoglycan of the isolated strain was meso-diaminopimelic acid and major respiratory isoprenoid quinone was MK-7. Major cellular fatty acids were anteiso-C15:0 (40.6 %), iso-C15:0 (20.7 %) and the DNA G+C content of strain FJAT-14515(T) was 37.1 mol %. A phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FJAT-14515(T) belongs to the genus Bacillus, and was most closely related to the reference strains of Bacillus muralis DSM 16288(T) (97.6 %) and Bacillus simplex DSM 1321(T) (97.5 %). Levels of DNA-DNA relatedness between strain FJAT-14515(T) and the reference strains of B. muralis DSM 16288(T) and B. simplex DSM 1321(T) were 27.9 % ± 3.32 and 44.1 % ± 0.57, respectively. Therefore, on the basis of phenotypic, chemotaxonomic and genotypic properties, strain FJAT-14515(T) represents a novel species of the genus Bacillus, for which the name Bacillus cihuensis sp. nov. is proposed. The type strain is FJAT-14515(T) (=DSM 25969(T) = CGMCC 1.12697(T)).

Bacillus bingmayongensis sp. nov., isolated from the pit soil of Emperor Qin's Terra-cotta warriors in China.

A Bacillus-like isolate, strain FJAT-13831(T), isolated from the No. 1 pit soil of Emperor Qin's Terra-cotta Warriors in Xi'an City, China, was studied to determine its taxonomic status. Dominant fatty acids of this organism included iso-C15:0, iso-C17:0, C16:0, iso-C13:0, anteiso-C15:0, and iso-C17:1ω5c. Comparative 16S rRNA gene sequence analysis confirmed the affiliation of this isolate to the genus Bacillus and indicated that it was closely related to Bacillus pseudomycoides DSM 12442(T) (99.72 % similarity). A phylogenetic analysis of the gyrB gene sequence similarities exhibited independent clustering of the isolate FJAT-13831(T) and showed 93.8 % (<95 %) sequence similarity with its closest phylogenetic neighbour B. pseudomycoides DSM 12442(T). Separate standing of the strain FJAT-13831(T) was supported by a whole genome-based phylogenetic analysis with an average nucleotide identity value of 91.47 (<95 %) between isolate FJAT-13831(T) and B. pseudomycoides DSM 12442(T) and was consistent with the results of DNA-DNA hybridization (69.1 % relatedness). These findings support the conclusion that the isolate FJAT-13831(T) represents a novel species, for which the name Bacillus bingmayongensis sp. nov. is proposed. The type strain is FJAT-13831(T) (= CGMCC 1.12043(T) = DSM 25427(T)).