Scheme showing predicted pyruvate fermentation pathway in <i>A</i>. <i>schaalii</i>.

<p>The genes found in <i>A</i>. <i>schaalii</i> suggest that pyruvate is either oxidatively decarboxylated to acetyl-CoA via pyruvate dehydrogenase (pdh) or it may be reduced to lactate by the action of lactate dehydrogenase or it may be converted to acetyl-CoA and formate by pyruvate-formate lyase. Acetyl-CoA may be converted into ethanol, during which 2 NADH are oxidized via a fused acetaldehyde/alcohol dehydrogenase encoded by <i>adhE</i>, ot it may be converted to acetate through an acetyl phosphate intermediate using phosphotransacetylase (pta) and acetate kinase (ack) with the concomitant production of ATP. Abbreviations: LDH, L-lactate dehydrogenase; PTA, phosphotransacetylase; AK, acetate kinase.