Studies on fermentation conditions for cellulolytic enzymes production using trichoderma viride QM 9414

Abstract

Efficient utilization of cellulosic materials as renewable resources is drawing increasing degree of attention in the scientific community. As part of our endeavor to improve the production of cellulase complex system, several factors that influence production of cellulolytic enzyme system have been studied. Those factors studied are: cellulose source, medium composition, aeration and surfactant etc.. The effects of temperature, pH and metal ions on cellulase activity and stability were also studied. For the production of cellulolytic enzymes using $\mbox{\underline{T}}$. $\mbox{\underline{viride}}$ QM 9414, optimal concentration of $KH_2PO_4$ was 0.01M. Casitone was a good protein source compared with others studied, such as peptone, yeast extract, tryptone and casein. Optimum concentration of glucose and Tween 80 was 0.3\% for cellulase production. Using rice straw as carbon source, the final pH was about 7, and cellulose medium supplemented with rice straw resulted in high productivity of cellulolytic enzymes particularly in cellobiase and moderate pH changes during fermentation process, 3.5 to 7. Optimal oxygen transfer rate was found to be about 50 mM $O_2/\ell$ for enzyme production. Optimum pH and temperature of cellulolytic enzyme was 5.2 and 60$^\circ$C, respectively. The highest stability of CMC activity and FP activity was obtained about 5.2 and 4.6 of pH value respectively at 50$^\circ$C. At 50$^\circ$C FP activity was more stable than CMC activity. Copper ion inhibited enzyme activity markedly at 0.1\% concentration.