Gene sequences of key acetogenic clostridial species were sequenced and isolated. Genes of interest were identified, and functionality was established. Key genes of interest for metabolic catalyzing activity in clostridial species include a three-gene operon coding for CODH activity, a two-gene operon coding for PTA-ACK, and a novel acetyl coenzyme A reductase. The promoter regions of the two operons and the acetyl coA reductase are manipulated to increase ethanol production.