CONDITIONS OF CELLULASE PRODUCTION BY A TRICHODERMA REESEI STRAIN AND OPTIMIZATION OF CELLULASE SYSTEM

The proper carbon and nitrogen source in liquid medium and optimal cultivating conditions for cellulase synthesis by a Trichoderma reesei strain were studied. The optimal carbon and nitrogen source (g/L) were: wheat straw 15, bran 5, urea 10-15,(NH4)2SO4 12 and NH4NO3 5. The optimal cultivating conditions were: inoculum age 72h, inoculum size 2×107 spore/mL, cultivating temperature 30-32℃ , pH 5.0, cultivating period 144h, inoculum shaking rate 180 r/min and medium volume 75mL in 250mL flask. The mixed submerge cultivation of T.reesei and Aspergillus niger with a spore ratio of 60∶1 showed that A. niger significantly enhanced the enzyme activity, βglucanase activity was 2.9 times higher than control. Under the optimal conditions,βglucanase activity and FPA activity achieved were 127.6 U/mL and 84.8 U/mL,respectively