Figure 1

Schematic diagram of the mechanisms involved in the response to increases in NADPH demand. Increases in NADPH demand were imposed by adding acetoin to the growth medium of a strain overexpressing an engineered NADPH-dependent butanediol dehydrogenase (NADPH-Bdh1p). Using the DynamoYeast model, we previously predicted that the glycerol-DHA cycle (dashed line) acts as a transhydrogenase system, supplying additional NADPH in response to high NADPH demand [5]. DHA: dihydroxyacetone; DHAP: dihydroxyacetone phosphate.