US 20150024450 on alcoholic fermentation to produce ethanol

From within US 20150024450 to Mascoma:


Ethanologenic organisms, such as Zymomonas mobilis, Zymobacter palmae, Acetobacter pasteurianus, or Sarcina ventriculi, and some yeasts (e.g., Saccharomyces cerevisiae), are capable of a second type of anaerobic fermentation, commonly referred to as alcoholic fermentation, in which pyruvate is metabolized to acetaldehyde and CO.sub.2 by pyruvate decarboxylase (PDC). Acetaldehyde is then reduced to ethanol by ADH regenerating NAD.sup.+. Alcoholic fermentation results in the metabolism of one molecule of glucose to two molecules of ethanol and two molecules of CO.sub.2. If the conversion of pyruvate to undesired organic acids could be avoided, as detailed above, then such a genetically modified microorganism would have an increased ability to produce ethanol as a fermentation product.