초록
<P><B>Abstract</B></P> <P>The aim of this work was to study the physico-chemical pretreatment and enzymatic hydrolysis of cotton stalk for ethanol production by <I>Saccharomyces cerevisiae</I>. Firstly, factors affecting pretreatment were screened out by Plackett-Burman design (PBD) and most significant factors were further optimized by Box-Behnken design (BBD). As shown by experimental study, most significant factors were FeCl<SUB>3</SUB> concentration (FC), irradiation time (IT) and substrate concentration (SC) affecting pretreatment of cotton stalk among all studied factors. Under optimum conditions of pretreatment FC 0.15mol/l, IT 20min and SC 55g/l, the release of reducing sugar was 6.6g/l. Hydrolysis of pretreated cotton stalk was done by crude on-site produced enzymes and hydrolysate was concentrated. Ethanol production by <I>Saccharomyces cerevisiae</I> using concentrated cotton stalk hydrolysate was 9.8g<SUB>p</SUB>/l, with ethanol yield 0.37g<SUB>p</SUB>/g<SUB>s</SUB> on consumed sugars. The data indicated that microwave FeCl<SUB>3</SUB> pretreated cotton stalk hydrolyses by crude unprocessed enzyme cocktail was good, and ethanol can be produced by fermentation of hydrolysate.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Optimization of pre-treatment using sequential statistical methodology. </LI> <LI> Pre-treated cotton stalk used for enzyme production. </LI> <LI> Hydrolysis of biomass by crude enzymes at bioreactor level. </LI> <LI> Concentration of hydrolysate and ethanol production. </LI> <LI> Energy production as well as solid waste management. </LI> </UL> </P>