Minimum nutritional requirements for cellular growth and extracellular slime polysaccharide production by the human dental plaque bacterial mutant Actinomyces viscosus T14Av

The requirements were examined in chemically-defined media. Magnesium sulphate, potassium phosphate and adenine were essential for cellular growth and sodium bicarbonate and inositol further stimulated growth. The addition of sodium phosphate to this medium stimulated both cellular growth and slime production. In contrast, ammonium sulphate inhibited slime production. Biotin and thiamine stimulated cellular growth and nicotinic acid was essential for slime production. Glutamine, alanine and cystine were essential for cellular growth. A minimal medium which supported both good cellular growth and slime production for strain T14Av contained adenine, sodium bicarbonate, MgSO 4, inositol, glucose, KH 2PO 4, Na 2HPO 4, biotin, thiamine, nicotinic acid, arginine, glutamine, alanine and cystine.