A triphosphopyridine nucleotide dependent alcohol dehydrogenase from Leuconostoc mesenteroides.

Ethanol formation during glucose fermentation is a relatively common activity of microorganisms; a few species, including Leuconostoc mesenterodes, produce ethanol as a major fermentation end product. The significant results from experiments with various species on this subject are: (1) at least three different metabolic pathways are available for anaerobic conversion of glucose to ethanol (Koshland and Westheimer, 1950; Gunsalus and Gibbs, 1952; Gibbs and DeMoss, 1951) and (2) ethanol originates from distinct and different portions of the glucose molecule. L. meenteroide produces ethanol exclusively from carbon atoms 2 and 3 of glucose via a fermentative hexose monophosphate pathway (Gunsalus and Gibbs, 1952). During studies of possible 2-carbon precursors of ethanol with cell-free extracts of L. mesenteroide8, it was observed that reduced triphosphopyridine nucleotide (TPN) was oxidized rapidly in the presence of acetaldehyde. The presence of a diphosphopyridine nucleotide (DPN) dependent alcohol dehydrogenase has been established previously (DeMoss et al., 1951). The data to follow are presented as evidence for the eistence of a triphosphopyridine nucleotide specific alcohol dehydrogenase in cell-free extracts of L. me8enteroide&. Sable (1952) reported oxidation of reduced triphosphopyridine nucleotide by yeast extracts in the presence of acetaldehyde, which suggests the presence of a triphosphopyridine nucleotide linked alcohol dehydrogenase. Recently Stafford and Vennesland (1953) described triphosphopyridine nucleotide linked alcohol dehydrogenases in extracts prepared from wheat germ or parsley leaves. The value of triphosphopyridine nucleotide dependent alcohol dehydrogenase as a bio-