Three corn stover hydrolysates enzymatic hydrolysates prepared from acid and alkaline pretreatments separately and hemicellulosic hydrolysate prepared from acid pretreatment were evaluated in composition and fermentability For enzymatic hydrolysate from alkaline pretreatment ethanol yield on fermentable sugars and fermentation efficiency reached highest among the three hydrolysates meanwhile ethanol yield on dry corn stover reached 0 175 g/g higher than the sum of those of two hydrolysates from acid pretreatment Fermentation process of the enzymatic hydrolysate from alkaline pretreatment was further investigated using free and immobilized cells of recombinant Saccharomyces cerevisiae ZU-10 Concentrated hydrolysate containing 669 g/L glucose and 32 1 g/L xylose was utilized In the fermentation with free cells 41 2 g/L ethanol was obtained within 72 h with an ethanol yield on fermentable sugars of 0 416 g/g Immobilized cells greatly enhanced the ethanol productivity while the ethanol yield on fermentable sugars of 0 411 g/g could still be reached Repeated batch fermentation with immobilized cells was further attempted up to six batches The ethanol yield on fermentable sugars maintained above 0 403 g/g with all glucose and more than 92 83% xylose utilized in each batch These results demonstrate the feasibility and efficiency of ethanol production from corn stover hydrolysates (C) 2010 Elsevier B V All rights reserved