Nj. Cao et al., ETHANOL-PRODUCTION FROM CORN COB PRETREATED BY THE AMMONIA STEEPING PROCESS USING GENETICALLY-ENGINEERED YEAST, Biotechnology letters, 18(9), 1996, pp. 1013-1018
A new and effective pretreatment process for biomass conversion involv
es the steeping of biomass in 2.9 M NH4OH. This resulted in the removi
ng about 80-90% of the lignin along with almost all the acetate from c
ellulosic residues. Based on dry cellulose from corn cob, a high gluco
se yield of 92% was obtained after enzymatic saccharification of cellu
lose fraction. By using a genetically engineered, xylose-fermenting Sa
ccharomyces 1400(pLNH33) in the batch fermentation of a glucose-xylose
mixture from corn cob, an ethanol concentration of 47 g/L was obtaine
d within 36 h with 84% yield. In addition, an ethanol concentration of
45 g/L was obtained within 48 h with 86% yield using simultaneous sac
charification-fermentation process.