Bacillus lacisalsi sp. nov., a moderately haloalkaliphilic bacterium isolated from a saline–alkaline lake

Salipaludibacillus daqingensis sp. nov., a moderately halophilic bacterium isolated from an oilfield

A novel alkaliphilic, Gram-stain-positive, moderately halophilic, rod-shaped, endospore-forming, motile, facultatively anaerobic bacterium (DQ-9T) was isolated from a sediment sample collected from Daqing oilfield in China, and characterized by a polyphasic taxonomic approach. Strain DQ-9T formed yellow pigment and grew occurred at salinities of 1-12 % (w/v) NaCl (optimum, 8 %) and at 10-40 °C (optimum, 30-35 °C), at pH 7.5-10.5 (optimum, pH 9.0-9.5). It was catalase-positive, but oxidase-negative. Based on the analysis of 16S rRNA gene sequences, DQ-9T was classified into the genus Salipaludibacillus and exhibited the highest similarities (98.37 %) to Salipaludibacillus neizhouensis JSM 071004T. Digital DNA-DNA hybridization and average nucleotide identity values between strain DQ-9T and the most closely related strain, S. neizhouensis DSM 19794T, were determined to be 72.0 and 21.6 %, respectively. The polar lipids were constituted by diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids (>5 %) comprised anteiso-C15 : 0, anteiso-C17 : 0, iso-C17 : 0, iso-C15 : 0 and C16 : 0. The cell-wall peptidoglycan contained meso-diaminopimelic acid, and menaquinone-7 was identified as the primary respiratory quinone. The DNA G+C content was 37.5 mol%. Through chemotaxonomic, physiological, and biochemical characterization, strain DQ-9T could be clearly distinguished from the closest Salipaludibacillus species. Based on provided data, strain DQ-9T is proposed to represent a novel species, Salipaludibacillus daqingensis sp. nov., within the genus Salipaludibacillus. The type strain is DQ-9T (=ACCC 60415T=KCTC 33936T).

Proposal to transfer Bacillus lacisalsi Dong et al. 2021 to the genus Alteribacter as Alteribacter lacisalsi comb. nov

In the present study, the taxonomic position of Bacillus lacisalsi YSP-3T was evaluated using phylogenetic and genome-based comparison. B. lacisalsi YSP-3T showed the highest 16S rRNA gene sequence similarity to Alteribacter natronophilus M30T (98.4 %), followed by Alteribacter aurantiacus K1-5T (97.5 %) and Alteribacter populi FJAT-45347T (97.2 %). In phylogenetic (based on 16S rRNA gene sequences) and phylogenomic (based on 71 bacterial single-copy genes) trees, B. lacisalsi YSP-3T clustered with the members of the genus Alteribacter . The amino acid identity (AAI) values between B. lacisalsi YSP-3T and the members of the genus Alteribacter were >65 %, which is above the cut-off level (65–95 %) for genus delineation. The average nucleotide identity (ANI) values between B. lacisalsi YSP-3T and the members of the genus Alteribacter were <95 %, which is lower than the threshold value (95–96 %) for bacterial species delineation. The AAI value suggested that B. lacisalsi YSP-3T was a member of the genus Alteribacter while the ANIb value suggested it as a novel species of the genus Alteribacter . Based on the results, we propose to transfer Bacillus lacisalsi to the genus Alteribacter as Alteribacter lacisalsi comb. nov.

Alteribacter keqinensis sp. nov., a moderately halophilic bacterium isolated from a soda lake

A Gram-stain-positive, aerobic, endospore-forming and rod-shaped bacterium (KQ-3^T), which grew at 10-45 °C (optimum 35 °C), pH 8.0-10.5 (optimum pH 9.0) and in the presence of 0-16 % (w/v) NaCl (optimum 3.0 %), was isolated from a soda lake and identified as representing a novel species using a polyphasic taxonomic approach. Strain KQ-3^T was catalase-positive, oxidase-negative and non-motile. Phylogenetic analysis based on 16S rRNA gene sequence affiliated KQ-3^T to the genus Alteribacter and showed the highest similarities to Alteribacter natronophilus M30^T (97.90 %), Alteribacter aurantiacus K1-5^T (97.84 %) and Alteribacter populi FJAT-45347^T (97.22 %). Digital DNA-DNA hybridization and average nucleotide identity analyses revealed that KQ-3^T displayed 21.4 and 72.81% genomic DNA relatedness with the most closely related strain, A. natronophilus M30^T, respectively. KQ-3^T contained all of the conserved signature indels that are specific for members of the genus Alteribacter. The DNA G+C content was 45.03 mol%. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the polar lipids consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and one unidentified phospholipid. The predominant menaquinone was MK-7 (100%) and the major fatty acids (>10 %) comprised anteiso-C_15 : 0, iso-C_15 : 0 and iso-C_16 : 0. Based on the data from the current polyphasic studies, KQ-3^T represents a novel species of the genus Alteribacter, for which the name Alteribacter keqinensis sp. nov. is proposed. The type strain is KQ-3^T (=ACCC 61799^T=KCTC 33933^T).

Bacillus pasinlerensis sp. nov., a thermophilic bacterium isolated from a hot spring in Turkey

A Gram-reaction-positive, endospore-forming bacterium, designated strain P1^T, was isolated from water samples collected from Pasinler Hot Spring and characterized using a polyphasic approach to clarify its taxonomic position. Strain P1^T was found to have chemotaxonomic and morphological characteristics consistent with its classification in the genus Bacillus. The strain shared the highest 16S rRNA gene sequence identity values with Bacillus thermolactis R-6488^T (97.6 %) and Bacillus kokeshiiformis MO-04^T (97.2 %) and formed a distinct clade with both type strains in the phylogenetic trees based on 16S rRNA gene sequences. Strain P1^T could grow optimally at 55 °C and in the presence of 2 % NaCl. The organism was found to contain meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The predominant menaquinone was determined to be MK-7. The major cellular fatty acids were identified as iso-C_15 : 0, iso-C_17 : 0 and anteiso-C_17 : 0. Based upon the consensus of phenotypic and phylogenetic analyses, strain P1^T represents a novel species of the genus Bacillus, for which the name Bacillus pasinlerensis sp. nov. is proposed. The type strain is P1^T (=DSM 107529^T=CECT 9885^T=NCCB 100674^T).