چكيده به لاتين
Abstract:
Given the importance and application of cellulase enzymes, the most important issue is now to find the optimum conditions of maximum enzyme production at a minimal cost. In this regard, in this study the production of cellulase enzyme with Trichoderma ressei PTCC 5142 on four types of cheap lignocellulosic substrates (corn germ, corn bran, sawdust, and wheat bran) and various combinations of of sawdust and wheat bran as substrate were studied using solid state fermentation for 6 days in flask scale. In addition, the effect of various aeration rates on the amounts of the enzyme production in 0.5-liter packed-bed bioreactor were examined by combination of wheat bran and sawdust with a ratio of 3:1. Cellulase enzyme activity of two produced enzymes in the form of beta-1,4-exo glucanase (FPase) and endo-beta-1, 4-glucanase (CMCase) were meseared. Initial substrate moisture content, pH and temperature in the flask scale were set at 70% (w/w), 4.8 and 30 °C, respectively. The results showed that for all substrates, the activity of the endo-beta-1, 4-glucanase production was more than exo-beta-1, 4-glucanase. The most endoglucanase and exoglucanase enzyme activities in flask scale were achieved 13 and 6.4 U/gds on the sixth and third day respectively using a mixture of 75% wheat bran and 25% sawdust. Initial substrate moisture content, pH and temperature in the packed-bed bioreactor was respectively considered 70% (w/w), 5.2 and 28 °C. The packed-bed bioreactor aeration rate in three levels of 0.5, 1 and 1.5 (l / h.gds) were investigated. The results showed that the aeration rate has positive impact on the fungal growth and enzyme activity. The greatest amount of enzyme activity for endoglucanase and exoglucanase was respectively observed 36 and 10 (U /gds) at aeration rate of 1.5 (l/h.gds).
Keywords: Cellulase enzyme, Solis state fermentation, Trichoderma ressei, Lignocellulosic substrate, Packed-bed bioreactor, Aeration rate.
