D-gluconate + NAD(+) <=> 5-dehydro-D-gluconate + NADH + H(+)
d-gluconate + nad(+) <=> 5-dehydro-d-gluconate + nadh + h(+)
D-gluconate + NAD(+) <=> 5-dehydro-D-gluconate + NADH + H(+)
d-gluconate + nad(+) <=> 5-dehydro-d-gluconate + nadh + h(+)