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.

Biochemistry of coenzyme B12-dependent glycerol and diol dehydratases and organization of the encoding genes

“…The participation of glycerol dehydratase and 1,3propanediol dehydrogenase in glycerol fermentation has also been shown for some Lactobacillus species such as L. reuteri, L. buchneri and L. brevis [24,26,27]. In contrast to the mentioned enteric bacteria and clostridia, lactobacilli are not able to grow on glycerol as sole carbon and energy source.…”

The Use and Effects of Lactic Acid Bacteria in Malting and Brewing with Their Relationships to Antifungal Activity, Mycotoxins and Gushing: A Review

“…Reuterin is produced from glycerol by starving cells under anaerobic condi- tions, and the active compound reuterin is an equilibrium mixture of monomeric, hydrated monomeric, and cyclic dimeric forms of 3-hydroxypropionaldehyde, produced by Lactobacillus reuteri 198 . Its activity is thought to be due to inhibition of ribonucleotide reductase, the enzyme which universally catalyses the first step in DNA synthesis 51,199 .…”

Antagonistic activities of lactic acid bacteria in food and feed fermentations

“…A coenzyme Bx2-dependent glycerol dehydratase catalyses conversion of glycerol into reuterin, and an NAD +dependent oxidoreductase catalyses reduction of reuterin to 1,3.propanediol. Both enzymes have been purified and characterized [141,143,144]. These enzymes constitute a pathway for use of glycerol as an alternate hydrogen acceptor by Lo.…”

“…reuteri during carbohydrate heterofermentations. Growth rates and cell yields are increased significantly when glycerol is available for this purpose [144]. A few other bacterial species, e.g., Kleb.…”