The nutritional requirements of 14 cultures ofBacillus coagulans, which were isolated and identified in this laboratory, and eight other authentic strains of this organism, were studied at 37 °C. Biotin and thiamine were required by all strains in a semisynthetic medium containing enzymatic casein hydrolyzate, glucose, and mineral salts. In addition, one strain required niacin. An additional requirement for folic acid (or PABA) was noted for most strains in a synthetic medium. With few exceptions, the amino acid requirements were non-specific. Glutamic acid appeared essential for a few strains and stimulated others.