PRODUCTS OF GLUCOSE METABOLISM BY HOMOFERMENTATIVE STREPTOCOCCI UNDER ANAEROBIC CONDITIONS

Abstract

The products of glucose metabolism by the streptococci tested (Streptococcus lactis, S. cremoris, S. liquefaciens, S. faecalis, S. thermophilus, and S. durans) are lactic, acetic, and formic acids, carbon dioxide, ethanol, glycerol, biacetyl, acetoin, and 2,3-butanediol. Although slight qualitative and quantitative differences were observed between the cultures in the products formed, the products other than lactate accounted for less than 18% of the glucose C. The expected equimolar ratios of 1- and 2-C products were not found; instead, a relatively con-stant proportion of the 1-C products seemed to be converted to acetate. Carbon-dioxide-fixation as a method for accomplishing this conversion was demonstrated with S. lactis, S. cremoris, and S. liquefaciens.