Evaluation of nonionic adsorbent resins for removal of inhibitory compounds from corncob hydrolysate for ethanol fermentation

The aim of this study was to investigate the effect of XAD4-column treatment on removal of several fermentation inhibitors from corncob hydrolysate (CH). From analysis using a model hydrolysate, more than 99% of 5-hydroxy-methyl furfural, furfural and vanillin were removed by this treatment, and more than 97% of the total xylose, glucose and arabinose remained in the detoxified CH (DCH). The resulting DCH was tested as a substrate for ethanol production by Saccharomyces cerevisiae and Pichia stipitis. The highest ethanol levels for S. cerevisiae were 1.40 and 4.92 g l−1 in CH and DCH, respectively. For P. stipitis, the levels were 0 and 4.73 g l−1 in the CH and DCH media, respectively. The levels of alcohol volumetric productivity in the DCH medium were 0.374 and 0.200 g l−1 h−1 for S. cerevisiae and P. stipitis, respectively.