Simultaneous saccharification and co-fermentation for improving the xylose utilization of steam exploded corn stover at high solid loading

Abstract

Simultaneous saccharification and co-fermentation (SSCF) of steam exploded corn stover (SECS) was investigated at 5–25% solid loadings compared with other conversion processes. SECS was washed with a 15-fold excess of deionized water to remove inhibitors of hydrolysis and fermentation. The concentration, yield, and productivity of ethanol was 34.3g/L, 90.0%, 2.61g/L/h in the co-fermentation of 60g/L glucose and 10g/L xylose by Saccharomyces cerevisiae IPE003. Ethanol concentration and productivity increased with increasing solid loading while ethanol yield decreased in all conversion processes of SECS. Glucan and xylan conversion was 82.0% and 82.1% in SSCF at 20% solid loading, respectively, while the concentration, yield and productivity of ethanol was 60.8g/L, 75.3% and 0.63g/L/h. The feeding strategy of SECS addition within 24h improved the SSCF performance. Therefore, SSCF increased ethanol productivity and was an effective conversion process for ethanol production at high solid loading.