The cellulose-rich fiber byproduct stream of corn dry milling (wet cake), is a potential feedstock for hybrid corn-and-cellulosic ethanol production.  To simulate process we prepared a high solids (30% w/w) slurry from wet cake in light stillage from a dry grind ethanol plant using laboratory-scale reactors.  The slurry was pretreated under liquid hot water conditions and hydrolyzed with a mixture of cellulases and hemicellulases resulting in a hydrolysate containing 115 g/L glucose, 55 g/L xylose and 46 g/L arabinose.  This hydrolysate was subsequently fermented with the Purdue glucose/xylose co-fermenting Saccharomyces cerevisiae 424A (LNH-ST).  Results of the fermentation showed very strong inhibition effecting utilization of both xylose and glucose.Potential sources include: concentration of secreted yeast metabolic products, osmotic stress or lack of free water from the high total dissolved solids, compounds liberated during the enzymatic deconstruction of the hemicelluloses and concentrated dissolved solids (non-protein) in the enzyme solutions.  In order to study the combined effects, artificial hydrolysates were prepared YEP media or corn steep liquor in water with the addition of potential fermentation inhibitors.  In comparison fermentations, potential inhibitors were selectively removed from artificial hydrolysates by a bed of adsorbent resins.