Alcohol fermentation of enzymatic hydrolysate of exploded rice straw by Pichia stipitis.

The xylose in an enzymatic hydrolysate of steam-exploded rice straw was not consumed by Pichia stipitis until the glucose was almost exhausted. A diauxic lag of 2 to 3 h in both cell growth and ethanol production occurred as metabolism switched from glucose to xylose utilization. Ethanol production was maximal [6 g ethano/l from 15 g reducing sugars/l (78% theoretical yield)] at an aeration rate of 0.2 vol/vol. min.