Genome-based reclassification of Evansella polygoni as a later heterotypic synonym of Evansella clarkii and transfer of Bacillus shivajii and Bacillus tamaricis to the genus Evansella as Evansella shivajii comb. nov. and Evansella tamaricis comb. nov

Genome-Based Reclassification of Anoxybacillus geothermalis Filippidou et al. 2016 as a Later Heterotypic Synonym of Anoxybacillus rupiensis Derekova et al. 2007

In this study, our aim was to elucidate the relationship between Anoxybacillus rupiensis DSM 17127T and Anoxybacillus geothermalis GSsed3T through whole-genome phylogenetic analysis. The obtained 16S rRNA gene sequence from the genome of A. rupiensis DSM 17127T exhibited a 99.8% similarity with A. geothermalis GSsed3T. In the phylogenetic trees constructed using whole-genome sequences and 16S rRNA gene sequences, A. rupiensis DSM 17127T and A. geothermalis GSsed3T were observed to form a clade, indicating a close relationship between them. Moreover, the average amino acid identity, average nucleotide identity, and digital DNA-DNA hybridization values calculated between A. rupiensis DSM 17127T and A. geothermalis GSsed3T exceeded the threshold values typically used for species demarcation. Furthermore, the phylogenomic analysis based on the core genome of the strains in question provided additional support for the formation of a monophyletic clade by A. rupiensis DSM 17127T and A. geothermalis GSsed3T. Most phenotypic and chemotaxonomic features between both strains were almost identical except for a few exceptions. These findings suggest that both strains should be classified as belonging to the same species, and we propose that A. geothermalis GSsed3T is a later heterotypic synonym of A. rupiensis DSM 17127T.

Assessing the metabolism, phylogenomic, and taxonomic classification of the halophilic genus Halarchaeum

In this study, a genomic approach was employed to evaluate the metabolic potentials and taxonomic classification of the halophilic genus Halarchaeum. Genomic analysis revealed that Halarchaeum members exhibit a predilection for amino acids as their primary energy source in high-salinity environments over carbohydrates. Genome analysis unveiled the presence of crucial genes associated with metabolic pathways, including the Embden-Meyerhof pathway, semi-phosphorylative Entner-Doudoroff pathway, and the urea cycle. Furthermore, the genomic analysis indicated that Halarchaeum members employ diverse mechanisms for osmotic regulation (encompassing both salt-in and salt-out strategies). Halarchaeum members also encode genes to alleviate acid and heat stress. The average nucleotide identity value between Halarchaeum solikamskense and Halarchaeum nitratireducens exceeded the established threshold (95%-96%) for defining distinct species. This high similarity suggests a close relationship between these two species, prompting the proposal to reclassify Halarchaeum solikamskense as a heterotypic synonym of Halarchaeum nitratireducens. The results of this study contribute to our knowledge of taxonomic classification and shed light on the adaptive strategies employed by Halarchaeum species in their specific ecological niches.

Genome-based reclassification of Anoxybacillus salavatliensis Cihan et al. 2011 as a later heterotypic synonym of Anoxybacillus gonensis Belduz et al. 2003

In the present study, we aim to clarify the taxonomic positions of Anoxybacillus salavatliensis DSM 22626^T and Anoxybacillus gonensis G2^T by using whole genome phylogenetic analysis, biochemical and chemotaxonomic characteristics. The genome sequences of A. salavatliensis DSM 22626^T was not available in any database, so it was sequenced in this study. In phylogenetic trees drawn using whole genome sequences and 16S rRNA gene sequences, A. salavatliensis DSM 22626^T and A. gonensis G2^T clade together and showed high sequence similarity (99.3%) based on 16S rRNA gene. The average amino acid identity, average nucleotide identity and digital DNA-DNA hybridization values between A. salavatliensis DSM 22626^T and A. gonensis G2^T were found to be greater than the threshold values for species demarcation. Further, the phylogenomic analysis based on the core genome of the strains under study confirmed that A. salavatliensis DSM 22626^T and A. gonensis G2^T formed a monophyletic clade. Most phenotypic and chemotaxonomic features between both strains were almost identical except for a few exceptions. The present results show that A. salavatliensis DSM 22626^T is a later heterotypic synonym of A. gonensis G2^T.

Genome-based reclassification of Anoxybacillus karvacharensis Panosyan et al. as a later heterotypic synonym of Anoxybacillus kestanbolensis Dulger et al. 2004; A. flavithermus subsp. yunnanensis CCTCC AB2010187T Dai et al. 2011 as a later heterotypic synonym of A. tengchongensis DSM 23211T Zhang et al. 2011

In the present study, we attempted to clarify the taxonomic positions of Anoxybacillus karvacharensis K1^T, Anoxybacillus kestanbolensis NCIMB 13971^T, Anoxybacillus flavithermus subsp. yunnanensis CCTCC AB2010187^T, and Anoxybacillus tengchongensis DSM 23211^T using whole-genome phylogenetic analysis. The genome sequence of A. kestanbolensis NCIMB13971^T was not available in any database, so it was sequenced in this study. The 16S rRNA gene sequence obtained from the genome of A. kestanbolensis NCIMB13971^T had 99.93% similarity with A. karvacharensis K1^T. The average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (DDH) values between A. karvacharensis K1^T and A. kestanbolensis NCIMB13971^T and between A. flavithermus subsp. yunnanensis CCTCCAB 2010187^T and A. tengchongensis DSM 23211^T were greater than the threshold values for species demarcation. The present results indicate that A. karvacharensis K1^T is a later heterotypic synonym of A. kestanbolensis NCIMB13971^T; A. flavithermus subsp. yunnanensis CCTCCAB 2010187^T is a later heterotypic synonym of A. tengchongensis DSM 23211^T.

Evansella halocellulosilytica sp. nov., an alkali-halotolerant and cellulose-dissolving bacterium isolated from bauxite residue

An alkali and salt-tolerating strain FJAT-44876^T was isolated from the bauxite residue sample. The 16S rRNA gene sequence and phylogenetic analysis suggest that strain FJAT-44876^T was a member of the genus Evansella. It grew at 15-45 ℃ (optimum 20-25 ℃) and pH 6.5-11.0 (optimum pH 8.0-9.0) with 0-20% (w/v) NaCl (optimum 6-8%). The major fatty acids were anteiso-C_15:0, iso-C_15:0, anteiso-C_17:0, iso-C_17:0, and C_16:0. The cell wall peptidoglycan contained meso-diaminopimelic acid and MK-7 as the menaquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, and phosphatidylglycerol. The genomic DNA G+C content was 38.2%. The average nucleotide identity values between strain FJAT-44876^T and closely related members were below the cutoff level for species delineation. Thus, based on the above results, strain FJAT-44876^T represents a novel species of the genus Evansella, for which the name Evansella halocellulosilytica sp. nov., is proposed. The type strain is FJAT-44876^T (=CCTCC AB 2016264^T = DSM 104633^T).