Potassium-activated aldehyde dehydrogenase involved in acetate formation during anaerobic growth on glucose. acetaldehyde + H2O + NADP(+) = acetate + 2 H(+) + NADPH H2O + NADP(+) + propanal = 2 H(+) + NADPH + propanoate H2O + NAD(+) + propanal = 2 H(+) + NADH + propanoate Present with 22200 molecules/cell in log phase SD medium. Belongs to the aldehyde dehydrogenase family.