Fig. 4
From: Improved growth rate in Clostridium thermocellum hydrogenase mutant via perturbed sulfur metabolism
Overview of metabolic changes in C. thermocellum ΔhydG and ΔhydG Δech. When hydrogenases were inactivated (red X), flux to ethanol increased and sulfate reduction gene expression increased (blue). Furthermore, the alcohol dehydrogenase is mutated [11], allowing use of NADPH as a cofactor for ethanol production (red pathways). Simultaneously, flux to H2, lactate, and acetate decreased or was eliminated (gray pathways). Use of thioredoxin (Trx) and ferredoxin (Fd) as electron donors is inferred from genome annotation and has not been experimentally verified