Dissimilation of Glucose by Heterofermentative Lactic Acid Bacteria

Abstract

Glucose was fermented by Lactobacillus lycopersici, L. acidophilaerogenes, and L. mannitopoeus with a careful quantitative determination of products: CO2 (equivalent to sum of acetic acid and ethyl alcohol, lactic acid which was secondarily fermented to CO2 and acetic acid), glycerol, acetic acid and ethyl alcohol. A scheme of dissimilation of glucose is proposed consisting of: (a) splitting of hexose into two 3-carbon intermediates, (b) splitting of the 3-C intermediate into acetaldehyde, CO2 and active hydrogen or stabilization into lactic acid which is secondarily converted into pyruvic acid and active hydrogen, (c) conversion of hydrated pyruvic acid to acetic acid, CO2 and active hydrogen, (d) acetaldehyde is reduced to ethyl alcohol, (e) reduction of an intermediary (glyceric aldehyde?) to glycerol.