Carbohydbate Metabolism of Lactic Acid Cultures. I. Effects of Antibiotics on the Glucose, Galactose, and Lactose Metabolism of Streptococcus Lactis

Streptococcus lactis UN metabolized glucose, galaetose, and lactose and produced varying amounts of lactic, formic and acetic acids, carbon dioxide, ethanol, and glycerol. Lactic acid constituted the major product, accounting or 26 to 93% of the metabolized sugar. Possible mechanisms of production of the various metabolites are discussed. Under the conditions of the study, S. lactis, normMly a homofermenter, functioned as a heterofermenter. The results indicate that the organism metabolized the sugars partly through classical glyeolysis and partly through the hexosemonophosphate shunt pathway.