(R)-acetoin + NADH + H(+) => (R,S)-butane-2,3-diol + NAD(+)
(r)-acetoin + nadh + h(+) => (r,s)-butane-2,3-diol + nad(+)
(R)-acetoin + NADH + H(+) => (R,S)-butane-2,3-diol + NAD(+)
(r)-acetoin + nadh + h(+) => (r,s)-butane-2,3-diol + nad(+)