Enzymic hydrolysis of rice straw by crude cellulase from Trichoderma reesei

The cellulase system with a maximum FP cellulase activity of 1•30 IU/ml obtained from fermentation by T. reesei of alkali treated, steamed rice straw was employed at 26 FPU g−1 substrate for enzymatic saccharification. Production of reducing sugars (as glucose) at 268•5 mg−1 of rice straw treated with 4% sodium hydroxide in combination with 60 min of steam pressure (1•05 kg cm−2) was obtained in 48 h of incubation. Analysis of variance applied to the results of the effects of various factors revealed that a substrate concentration of 4% (w/v), a pH of 5•0, a temperature of 50°C, an enzyme concentration of 25 FPU g−1 substrate and a time of 48 h, were optimum for the production of the maximum amount of reducing sugars; 268•5 mg g−1 of pre-treated rice straw representing a maximum saccharification of 54•3% (cellulose basis).