Studies On Isolation Of Strains Producing Cellulase And Conditions Of Enzyme Production

The dissertation discussed the development of cellulose and cellulase. It also introduced the principle that cellulase how to decompose cellulose. The strain Trichoderma virde 13001 was adopted in this research. Proverbially it is a good enzyme producing stain. The purpose of the present study was to attain a better one than parent stain by mutation.Based on the Trichoderma virde 13001,a mutated strain 1.0-28 was obtained through treatments of ultraviolet radiation and 60Co- ? radiation. After each treatment, the optimum time of ultraviolet radiation, the optimum dosage of 60'Co- ? radiation and the rate of positive mutation were researched. The strain isolation in each treatment was divided into two phases. First isolation was according to the test of filter paper collapse. Second isolation was according to the test of filter paper enzyme activity(FPase) . CMC-enzyme activity(CMCase) and 13 -glucosidase activity through liquid fermentation. The enzyme activity of the strain 1.0-28 was higher than parent stain. The result of higher were: FPase was 34.02%,CMCase was 31.13%, P -glucosidase was 23.87%The dissertation also studied the optimal conditions of enzyme production on the strain 1.0-28.The results showed that the better condition were: the carbon sources was straw powder, the ratio of straw powder and wheat bran equal 2:l,with (NH4)2SO4 as nitrogensources, cultural originally pH was 5.5,cultural temperature was 30 ?cultural time was 120-130h,the quantity of inoculability was 2-3%. The emulsifier Tween80 and the age of the strain had not obvious effect on the result.