Utilization of glycerol as a hydrogen acceptor by Lactobacillus reuteri: Purification of 1,3-propanediol:NAD+ oxidoreductase

Abstract

Lactobacillus reuteri utilizes exogenously added glycerol as a hydrogen acceptor during carbohydrate fermentations, resulting in higher growth rates and cell yields than those obtained during growth on carbohydrates alone. Glycerol is first converted to 3-hydroxypropionaldehyde by a coenzyme B12-dependent glycerol dehydratase and then reduced to 1,3-propanediol by an NAD+-dependent oxidoreductase. The latter enzyme was purified and determined to have a molecular weight of 180,000; it is predicted to exist as a tetramer of identical 42,000-molecular-weight subunits.