Taxonomic Description and Genomic Characterization of Saccharibacillus soli sp. nov., Isolated from Copper Mine Soil, Khetri, Rajasthan, India

Gram-stain-positive, endospore-producing, mesophilic and rod-shaped strain O16T was isolated from a copper mine’s soil and characterized using a polyphasic taxonomic approach. The 16S rRNA gene-sequence analysis revealed that strain O16T belongs to the genus Saccharibacillus. It exhibited the highest sequence similarity to Saccharibacillus endophyticus JM-1350T (97.2%), followed by ‘Saccharibacillus alkalitolerans’ VR-M41T (97.1%), Saccharibacillus sacchari GR21T (96.8%), Saccharibacillus kuerlensis HR1T (96.6%), and Saccharibacillus deserti WLJ055T (95.7%). Genome-based comparisons revealed that the digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain O16T and its closest relatives, S. endophyticus JM-1350T and ‘S. alkalitolerans’ VR-M41T, were 21.3% and 22.3%, and 76.6% and 77.6%, respectively, which are well below the recommended thresholds for species delineation. The diagnostic diamino acid of the cell wall was meso-diaminopimelic acid. Phosphatidylglycerol and diphosphatidylglycerol were the major polar lipids in strain O16T. The predominant menaquinone was MK-7. The DNA G+C content was 53.4%. The major cellular fatty acids present were anteiso-C15:0 (60.8%), iso-C16:0 (9.5%) and C16:1 ω11c (7.4%). On the basis of phenotypic, chemotaxonomic, and genotypic evidence, strain O16T is considered to represent a novel species within the genus Saccharibacillus. This data strongly supports the classification of the strain O16T as a novel species in the genus Saccharibacillus, for which we propose the name Saccharibacillus soli sp. nov. strain O16T (=CCM 8781T = KCTC 33898T).