calculibacillus calculibacillus calculibacillus is a gram-positive, non-spore-forming and strictly anaerobic genus of bacteria from the family of bacillaceae with one known species (calculibacillus koreensis). calculibacillus koreensis has been isolated from sediments of a coal mine in taebaek. calculibacillus scientific classification domain: bacteria phylum: bacillota class: bacilli order: bacillales family: bacillaceae genus: calculibacillusmin et al. 2021 type species calculibacillus koreensis species c. koreensis