Abstract

MOLINA, C.; SANCHEZ, A.; SERAFIN-MUNOZ, A.  and  FOLCH-MALLOL, J.. Optimization of enzymatic saccharification of wheat straw in a micro-scale system by reponse surface methodology. Rev. Mex. Ing. Quím [online]. 2014, vol.13, n.3, pp.765-778. ISSN 1665-2738.

This paper studies the combined effects of temperature, pH and enzyme-substrate ratio (E/S_R) on hydrolysis yield and specific reaction rate (S_RV) in a microscale iystem in order to maximize enzymatic hydrolysis of pretreated wheat straw (WS). The WS was pretreated by alkaline -peroxide. Enzymatic complex Accellerase 1500^TM was used for hydrolysis assays. Using response surface methodology, optimal parameter values were determined. A complete enzymatic kinetic of the hydrolysis reaction was obtained in 10 h. The optimal value of reducing sugars concentration (RS_c), given by the model, was 5.97 mg/mL and the corresponding yield was 61.73%. The maximum yield for the WS hydrolysis was 61.73% and was achieved at a temperature of 52.0°C, pH 4.6, and a E/S_R of 2.1 mL of Accellerase 1500^TM/g of cellulose. The S_RV was 4.80 U/mg and was obtained with the following conditions: pH 5.0, temperature of 48.5°C and an E/S_R of 0.19 mL/g. A quadratic polynomial equation for predicting the hydrolysis yield was developed. The confirmation experiment showed a final value for RS_c of 5.98 ± 0.81 mg/mL. This result indicates a % error of 0.33. The experimental results were in good agreement with predicted value.

Keywords : enzymatic saccharification; wheat straw; response surface methodology; microscale system.