Bacillus coagulans is a lactic acid forming bacterial species within the genus Bacillus. t was initially considered to be a spore-forming Lactobacillus. Since Bacillus coagulans exhibits characteristics typical of both genera Lactobacillus and Bacillus, its taxonomic position between the families Lactobacillaceae and Bacillaceae was often debated. B. coagulans is a Gram-positive rod (0.9μm by 3.0μm to 5.0μm in size); catalase positive, spore-forming, motile, a facultative anaerobe. B. coagulans may appear Gram-negative when entering the stationary phase of growth. The optimum temperature for growth is 50 °C; range of temperatures tolerated is 30°C - 55°C. IMViC Tests VP and MR (methyl-red) tests are positive.