Diacetyl (Acetoin) Reductase from <i>Aerobacter aerogenes</i>

Abstract

The kinetics of the reversible reduction of acetoin and NADH to 2,3‐butanediol and NAD by diacetyl (acetoin) reductase from Aerobacter aerogenes , have been investigated at pH 7.0, 5.8, and 4.8. The reaction follows an ordered bi‐bi mechanism. Acetate acts as an inhibitor of the enzyme with respect to the substrate 2,3‐butanediol. This inhibition increases for decreasing pH, indicating that it is acetic acid that is the effector. These results, in combination with earlier observations, show that high acetate concentration allows maximal 2,3‐butanediol and NAD production at 5.8 from pyruvate and NADH.