Can oxidize benzaldehyde, propionaldehyde and acetaldehyde. No detectable activity with retinal. an aldehyde + H2O + NAD(+) = a carboxylate + 2 H(+) + NADH The highest catalytic efficiency is observed with benzaldehyde as substrate. No activity with retinal. Alcohol metabolism; ethanol degradation; acetate from ethanol: step 2/2. Homotetramer. Very low levels in lung and liver. By phenobarbital. Belongs to the aldehyde dehydrogenase family.