Taxonomic insights into the phylogeny of Bacillus badius and proposal for its reclassification to the genus Pseudobacillus as Pseudobacillus badius comb. nov. and reclassification of Bacillus wudalianchiensis Liu et al., 2017 as Pseudobacillus wudalianchiensis comb. nov

Phylogenomic evaluation of Mangrovimicrobium sediminis gen. nov. sp. nov., the first nitrogen fixing member of the family Halieaceae adapted to mangrove habitat and reclassification of Halioglobus pacificus to Pseudohaliglobus pacificus comb. nov

The taxonomic position and genomic characteristics of a nitrogen fixing and polymer degrading marine bacterium, strain SAOS 164 isolated from a mangrove sediment sample was investigated. Sequence analysis based on 16S rRNA gene identified it as a member of family Halieaceae with closest similarity to Haliea salexigens DSM 19537T (96.3 %), H. alexandrii LZ-16-2T (96.2 %) and Parahaliea maris HSLHS9T (96.0 %) but was distantly related to the genera Haliea, Parahaliea and Halioglobus in phylogenetic trees. In order to ascertain the exact taxonomic position, phylogeny based on RpoBC proteins, whole genome, core and orthologous genes, and comparative analysis of metabolic potential retrieved the strain in an independent lineage clustering along with the genera Halioglobus, Pseudohalioglobus and Seongchinamella. Further, various genome based delimitation parameters represented by mol % GC content, percentage of conserved proteins (POCP), and amino acid identity (AAI) along with chemotaxonomic markers (i.e. fatty acids and polar lipids) supported the inferences of genome based phylogeny and indicated that the strain SAOS 164 belongs to a novel genus. The genome was mapped to 4.8 Mb in size with 65.1 % DNA mol% G + C content. In-silico genomic investigation and phenotyping revealed diverse metabolite genes/pathways related to polymer hydrolysis, nitrogen fixation, light induced growth, carbohydrate, sulfur, phosphorus and amino acid metabolism, virulence factors, defense mechanism, and stress-responsive elements facilitating survival in the mangrove habitat. Based on polyphasic taxonomic approach including genome analyses, a novel genus Mangrovimicrobium sediminis gen. nov. sp. nov. (=SAOS 164T = MTCC 12907T = KCTC 52755T = JCM 32136T) is proposed. Additionally, the reclassification of Halioglobus pacificus (=DSM 27932T = KCTC 23430T = S1-72T) to Pseudhalioglobus pacificus comb. nov. is also proposed.

Genome-based classification of Calidifontibacillus erzurumensis gen. nov., sp. nov., isolated from a hot spring in Turkey, with reclassification of Bacillus azotoformans as Calidifontibacillus azotoformans comb. nov. and Bacillus oryziterrae as Calidifontibacillus oryziterrae comb. nov

A novel Gram-stain-positive, rod-shaped, endospore-forming, motile, aerobic bacterium, designated as P2^T, was isolated from a hot spring water sample collected from Ilica-Erzurum, Turkey. Phylogenetic analyses based on 16S rRNA gene sequence comparisons affiliated strain P2^T with the genus Bacillus, and the strain showed the highest sequence identity to Bacillus azotoformans NBRC 15712^T (96.7 %). However, the pairwise sequence comparisons of the 16S rRNA genes revealed that strain P2^T shared only 94.7 % sequence identity with Bacillus subtilis subsp. subtilis NCIB 3610^T, indicating that strain P2^T might not be a member of the genus Bacillus. The digital DNA-DNA hybridization and average nucleotide identity values between strain P2^T and B. azotoformans NBRC 15712^T were 19.8 and 74.2 %, respectively. The cell-wall peptidoglycan of strain P2^T contained meso-diaminopimelic acid. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an aminophospholipid, five unidentified phospholipids and two unidentified lipids while the predominant isoprenoid quinone was MK-7. The major fatty acids were iso-C_15 : 0 and iso-C_16 : 0. The draft genome of strain P2^T was composed of 82 contigs and found to be 3.5 Mb with 36.1 mol% G+C content. The results of phylogenomic and phenotypic analyses revealed that strain P2^T represents a novel genus in the family Bacillaceae, for which the name Calidifontibacillus erzurumensis gen. nov., sp. nov. is proposed. The type strain of Calidifontibacillus erzurumensis is P2^T (=CECT 9886^T=DSM 107530^T=NCCB 100675^T). Based on the results of the present study, it is also suggested that Bacillus azotoformans and Bacillus oryziterrae should be transferred to this novel genus as Calidifontibacillus azotoformans comb. nov. and Calidifontibacillus oryziterrae comb. nov., respectively.

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.

Halocatena pleomorpha gen. nov. sp. nov., an extremely halophilic archaeon of family Halobacteriaceae isolated from saltpan soil

A novel archaeal strain designated as SPP-AMP-1T was isolated from saltpan soil, using the serial dilution method on a halophilic archaeal medium supplemented with ampicillin. Cells were both rod-shaped and pleomorphic in nature, non-motile, unable to produce acid from a variety of sugars or grow anaerobically with different substrates (l-arginine) and electron acceptors (DMSO, nitrate). Optimal growth was observed at 42 °C, 3.4–4.2 M NaCl and pH 7.2. Cells did not lyse in distilled water and grew in the absence of Mg2+ ions. Phylogenetic analysis based on the sequences of 16S rRNA gene, amino acid sequence of β′-subunit of RNA polymerase and 400 conserved proteins retrieved from the whole genome assemblies showed that strain SPP-AMP-1T was distantly related to any existing genera within the family Halobacteriaceae . MK-8 was the only quinone detected. Polar lipid analysis showed a unique combination of diethyl derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, glycosyl-mannosyl-glucosyl diether and sulphated glycosyl-mannosyl-glucosyl diether as the major lipids. The G+C content of genomic DNA is 57.7 mol%. The phenotypic, phylogenetic and genomic data supported the concept of the novel genus status of strain SPP-AMP-1T in the family Halobacteriaceae for which the name Halocatena pleomorpha gen. nov., sp. nov., is proposed; the type strain is SPP-AMP-1T (=JCM 31368T=KCTC 4276T=MTCC 12579T).