This work deals with optimization the production conditions of endoglucanase produced by Chaetomium globosum and its role in some lignocellulosic materials (corn stover) degradation. Optimization studies revealed that Reese and Mandel’s basal medium was the best for maximum endoglucanase secretion by C. globosum. Maximum endoglucanase production was found at 2.5% cellulose and 0.3% urea. C. globosum gave maximum endoglucanase production on Reese and Mandel’s basal medium at pH 6 and 8% (v/v) inoculum volume after 8 days of cultivation. Yield of endoglucanase and protein were 60.2 and 35.6%, respectively after concentration with ultrafiltration. Specific activity of endoglucanase was 2.17 U/mg. Kinetic studies of endoglucanase revealed 2.27 mg/mL as Km and 0.1194 µmol/min/mL as Vmax. Optimum temperature for endoglucanase activity was 65 °C, while the optimum pH was 5. Endoglucanase retained about 60 % of its activity when incubated at 65 °C for 2 h. While, the enzyme lost about 58% from its activity at 65 °C for 12h. Moreover, endoglucanase showed high stability for pH 5 when incubated for 12h. An isoelectric point (pI) around 4.5 was detected for endoglucanase. The molecular weight was calculated to be about 40 KDa. Application of endoglucanase on corn stover was assessed compared with cellulase produced from T. reesei and laminex enzyme. The three enzymes gave higher concentrations of reducing sugars when corn stover was treated with peroxidase (MsP1) than untreated one. Laminex enzyme showed the highest catalytic activity to hydrolyze polymeric carbohydrates of corn stover. Maximum level of lignin degradation can be reached after 24 hours with using 3 units of MsP1. |
