Abstract

Xylanase and endoglucanase production from Trichoderma viride HG 623 and their properties were investigated in this research. By using response surface methodology, the optimal concentrations for xylanase and endoglucanase production were carbon (rice straw: corn straw=6:1), 26.91 g/L; NH₄Cl, 3.77 g/L; KH₂PO₄, 5.31 g/L and carbon (rice straw:corn straw=6:1), 26.99 g/L; NH₄Cl, 3.80 g/L, and KH₂PO₄, 5.23 g/L, respectively. Under these optimal conditions, the xylanase and endoglucanase activity from T. virideHG 623 reached 135.51 and 40.89 IU/g, respectively. Verification of the optimization showed that xylanase and endoglucanase activity were 139.57 and 41.46 IU/g, respectively. The optimal pH of xylanase and endoglucanase activity from T. viride HG 623 was 5.0 and the optimal temperature were 60 and 55°C, respectively. The activity of xylanase and endoglucanase were stable when incubated from 35 to 55°C for 1 h. The xylanase and endoglucanase activity of T. viride HG 623 were stable from pH 3.0 to 7.5 at 50°C. Xylanase activity showed the highest level (150.36 IU/g) when activated by 75 mM of Co²⁺, and endoglucanase activity reached the highest level (36.99 IU/g) when activated by 75 mM of Mg²⁺. The wheat bran was the optimal natural substrate for enzyme production of T. viride HG 623. The results of this study would instruct the cellulase and hemicellulase production on industrial scale.

Key words: Trichoderma viride HG 623, xylanase, endoglucanase, response surface methodology, characterization.