2-5 Ethanol production from gaseous substrates by genetically engineered thermophilic acetogen Moorella thermoacetica

Abstract

Transgenic strains of M. thermoacetica in which aldehyde dehydrogenase gene (aldh) was introduced and pduL2 or both of phosphotransacylase genes, pduL1 and pduL2 were eliminated were constructed. Although all strains harboring aldh produced ethanol using fructose as a substrate, they didn’t produce ethanol from H₂-CO₂. However, a pdul2 deletion mutant produced formate, suggesting that insufficient ATP supply caused poor metabolism of H₂-CO₂.