Bacillus catenulatus sp. nov., an alkalitolerant bacterium isolated from a soda lake

Sutcliffiella rhizosphaerae sp. nov. isolated from roots

An aerobic, Gram-staining-positive, endospore-forming bacterium, isolated from the rhizosphere of roots of maize (Zea mays), was taxonomically studied. On the basis of 16S rRNA gene sequence similarity comparisons, strain JJ-125T clustered together with species of the genus Sutcliffiella and showed the highest similarities with Sutcliffiella zhanjiangensis (98.7 %). The 16S rRNA gene sequence similarities to the sequences of the type strains of other species of the genus Sutcliffiella were <98.4 %. The genome sequence of JJ-125T was 4 516 360 bp long and had a DNA G+C content of 37.3 %. A DNA–DNA hybridization with the type strain of S. zhanjiangensis DSM 23010T resulted in values of 42.3 and 43.9 % (reciprocal). The average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values between the JJ-125T genome assembly and those of the other type strains of species of the genus Sutcliffiella were <75%, <80 % and <21 %, respectively. Chemotaxonomic features supported the grouping of the strain with the genus Sutcliffiella, e.g. the major fatty acids included iso-C15 : 0, iso-C17 : 1 ω10c and iso-C17 : 0, the polar lipid profile contained the major components diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, the only quinone was menaquinone MK-7 and the characteristic diamino acid was meso-diaminopimelic acid. Physiological and biochemical test results were also different from those of the most closely related species. As a consequence, JJ-125T represents a novel species of the genus Sutcliffiella , for which we propose the name Sutcliffiella rhizosphaerae sp. nov., with JJ-125T (= CIP 111883T = LMG 32156T = CCM 9046T) as the type strain.

Sutcliffiella deserti sp. nov., isolated from desert soil

A Gram-stain-positive, facultative anaerobic, motile and rod-shaped bacterial strain, DG-18T, was isolated from desert soil sampled at the Kubuqi Desert in Inner Mongolia, China. Strain DG-18T grew at 4–40 °C (optimum, 25–30 °C), at pH 8.0–10.0 (optimum, pH 9.0) and with 0–8.0 % (w/v) NaCl (optimum 2.0%). 16S rRNA gene sequence analysis placed strain DG-18T within the genus Sutcliffiella of the family Bacillaceae with Sutcliffiella halmapala DSM 8723T (98.2%), Sutcliffiella zhanjiangensis JSM 099021T (97.6%), Sutcliffiella horikoshii DSM 8719T (97.4%), Sutcliffiella catenulata 18CT (96.6 %) and Sutcliffiella cohnii NBRC 15565T (96.5%) as its closest relatives. The major respiratory quinone of strain DG-18T was MK-7 and the major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Its major fatty acids were iso-C15 : 0 and iso-C17 : 1  ω10c. The genomic DNA G+C content of strain DG-18T was 38.7 mol% based on total genome calculations. The average nucleotide identity score between the genomic sequence of strain DG-18T and that of S. halmapala DSM 8723T was 76.7 %. The Genome-to-Genome Distance Calculator showed that the DNA–DNA hybridization value for strain DG-18T and S. halmapala DSM 8723T was 21.8%. Based on the polyphasic taxonomic data, strain DG-18T represents a novel species of the genus Sutcliffiella , for which the name Sutcliffiella deserti sp. nov. is proposed. The type strain is DG-18T (=GDMCC 1.17773T=KCTC 43170T).

Robust demarcation of 17 distinct Bacillus species clades, proposed as novel Bacillaceae genera, by phylogenomics and comparative genomic analyses: description of Robertmurraya kyonggiensis sp. nov. and proposal for an emended genus Bacillus limiting it only to the members of the Subtilis and Cereus clades of species

To clarify the evolutionary relationships and classification of Bacillus species, comprehensive phylogenomic and comparative analyses were performed on >300 Bacillus/Bacillaceae genomes. Multiple genomic-scale phylogenetic trees were initially reconstructed to identify different monophyletic clades of Bacillus species. In parallel, detailed analyses were performed on protein sequences of genomes to identify conserved signature indels (CSIs) that are specific for each of the identified clades. We show that in different reconstructed trees, most of the Bacillus species, in addition to the Subtilis and Cereus clades, consistently formed 17 novel distinct clades. Additionally, some Bacillus species reliably grouped with the genera Alkalicoccus, Caldalkalibacillus, Caldibacillus, Salibacterium and Salisediminibacterium. The distinctness of identified Bacillus species clades is independently strongly supported by 128 identified CSIs which are unique characteristics of these clades, providing reliable means for their demarcation. Based on the strong phylogenetic and molecular evidence, we are proposing that these 17 Bacillus species clades should be recognized as novel genera, with the names Alteribacter gen. nov., Ectobacillus gen. nov., Evansella gen. nov., Ferdinandcohnia gen. nov., Gottfriedia gen. nov., Heyndrickxia gen. nov., Lederbergia gen. nov., Litchfieldia gen. nov., Margalitia gen. nov., Niallia gen. nov., Priestia gen. nov., Robertmurraya gen. nov., Rossellomorea gen. nov., Schinkia gen. nov., Siminovitchia gen. nov., Sutcliffiella gen. nov. and Weizmannia gen. nov. We also propose to transfer 'Bacillus kyonggiensis' to Robertmurraya kyonggiensis sp. nov. (type strain: NB22=JCM 17569^T=DSM 26768). Additionally, we report 31 CSIs that are unique characteristics of either the members of the Subtilis clade (containing the type species B. subtilis) or the Cereus clade (containing B. anthracis and B. cereus). As most Bacillus species which are not part of these two clades can now be assigned to other genera, we are proposing an emended description of the genus Bacillus to restrict it to only the members of the Subtilis and Cereus clades.

Bacillus dafuensis sp. Nov., Isolated from a Forest Soil in China

A Gram-staining-positive, motile, rod-shaped, aerobic bacterial strain FJAT-25496 ^T was isolated from a forest soil sample collected from Dafu County, Chengdu City, Sichuan Province, China. Strain FJAT-25496 ^T grew at 15-50 °C (optimum 35 °C), pH 6.0-10.0 (optimum 8.0), and NaCl tolerance of 0-4.0% (w/v) (optimum 0%). The strain contained iso-C_15:0 and anteiso-C_15:0 as the predominant cellular fatty acids as well as MK-7 as the only menaquinone. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), and phosphatidyl glycerol (PG). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain FJAT-25496 ^T was a member of the genus Bacillus, and most closely related to Bacillus solani FJAT-18043 ^T (97.8%), Bacillus praedii FJAT-25547 ^T (97.8%), Bacillus depressus BZ1^T (97.7%), Bacillus oceanisediminis H2^T (97.7%), and Bacillus ciccensis 5L6^T (97.6%). Based on complete genome comparisons between strain FJAT-25496 ^T and the type strains of its closely related species, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values were 73.4-76.3% and 21.7-23.2%, respectively. The genomic DNA G + C content of strain FJAT-25496 ^T was 36.9%. On the basis of phenotypic, phylogenetic, chemotaxonomic, and genomic features, strain FJAT-25496 ^T is considered to represent a novel species of the genus Bacillus, for which the name Bacillus dafuensis sp. nov. is proposed. The type strain is FJAT-25496 ^T (= CCTCC AB 2019182 ^T = KCTC 43120 ^T).

Description of Bacillus kexueae sp. nov. and Bacillus manusensis sp. nov., isolated from hydrothermal sediments

Two Gram-staining-positive, strictly aerobic bacilli, designated as strains Ma50-5^T and Ma50-6^T, were isolated from the hydrothermal sediments of Manus Basin in the western Pacific Ocean. Based on 16S rRNA gene sequence, strains Ma50-5^T and Ma50-6^T were most closely related to Bacillus alveayuensis (97.0 and 97.2 % identity, respectively). The 16S rRNA gene sequence identity between strains Ma50-5^T and Ma50-6^T was 97.4 %. The identities between strains Ma50-5^T and Ma50-6^T and other closely related organisms were below 97.0 %. The G+C contents of the genomic DNA of strains Ma50-5^T and Ma50-6^T were 43.4 and 47.6 mol%, respectively. The major fatty acids (>10 %) of both strains were iso-C15 : 0 and iso-C17 : 0. The predominant isoprenoid quinone detected in both strains was menaquinone-7. Phylogenetic, physiological, biochemical and morphological analyses suggested that strains Ma50-5^T and Ma50-6^T represent two novel species of the genus Bacillus, for which the names Bacillus kexueae sp. nov. (type strain Ma50-5^T=KCTC 33881^T=CCTCC AB 2017020^T) and Bacillus manusensis sp. nov. (type strain Ma50-6^T=KCTC 33882^T=CCTCC AB 2017019^T), respectively, are proposed.