geobacillus geobacillus geobacillus is a bacterial genus from the family of bacillaceae. geobacillus geobacillus stearothermophilus'’ on agar plate scientific classification domain: bacteria phylum: bacillota class: bacilli order: bacillales family: bacillaceae genus: geobacillusnazina et al. 2001 type species geobacillus stearothermophilus species g. caldoxylosilyticus g. galactosidasius g. icigianus g. jurassicus g. kaustophilus g. lituanicus g. stearothermophilus g. subterraneus g. thermantarcticus g. thermocatenulatus g. thermodenitrificans g. thermoglucosidasius g. thermoleovorans g. toebii g.uzenensis g. vulcani