Cellulase Production And Production Alcohol From Corn Straw Through Solid-state Fermentation

Cellulose is the most abundant and broad organic material in the earth. Not only the kind of precious resource is not made full use but also most of them are abandoned and then became one of the pollution matters of the environment. After the enzymatic hydrolysis of cellulosic materials, the available reducing sugar could be used in the production of ethanol;it was promising in the comprehensive utilization of the residue and the control of the pollutant.In this experiment cellulase production was carried out by solid state fermentation with Trichoderma. Reesei LW1. The material was corn straw which is not only affluent but also cheap. The effects of wheat bran and corn stalk ratio, water content ratio, initial pH of medium, temperature, time on cellulase synthesis were studied. The results showed that the optimum conditions of producing cellulase were: under the above conditions of wheat bran and corn stalk ratio was 1:1, water content ratio was 1:2, through the analysis of factors and levels of orthogonal experiment, the temperature was 28℃, the initial pH was 5.5 and grown 72h the activities of FPase in the fermented was 271.363/u, the activities of CMCase in the fermented was 467.700/u.Enzyme properties of the crude enzyme from Trichoderma Reesei LW1 were studied. The optimal conditions for enzymatic reaction were 50℃,and pH value were 4.8;showed a high stability at temperature 30~50℃,pH4.0~~6.0;stayed 15min at 90℃, CMCase could be held 62.09%,and FPase could be held 60.84%;stayed 30min at the environment which was like the animal stomach, CMCase could be held 79.04%,and FPase could be held 76.44%;stayed 3 months at 4℃ and germfree condition, CMCase could be held 82.93%,and FPase could be held 79.89%;Ca~2+ K~+ Na~+ Mg~2+ were the activators and Mn~2+ Zn~2+ Cu~2+ were the inhibitors of the enzyme.The simultaneous saccharification and fermentation conditions of the ethanol production by corn straw were determined in orthogonal experiment and the followings were the optimal conditions: fermenting temperature 32℃, fermenting period 4d, the initial pH 5.0, cellulase weight 35 IU/g and inoculation of yeast was 10~8 cell/mL. At the optimal condition, the ethanol yield reached 4.67%. When 50% wheat bran was added into the. medium, the ethanol yield reach to the maximum The variety of corn straw had no effect to the production of ethanol.