Abstract

This work shows optimal conditions to use the amylases from A. niger in starch hydrolysis and alcohol production from manioc root starch. Bioreactors contained 10-20 g/L of manioc starch concentration, on 35-55°C, and at pH 4.8; they were made for the evaluation of the effects of starch concentration and temperature on hydrolysis yield. New models for starch hydrolysis kinetics were compared for substratum dependence ([S]) to the hydrolysis time (t) and hydrolysis conversion rate (V) dependences with the substratum concentration ([S]). Results showed that exponential models fitted better than other models. The appropriate models were [S] = e^-k.t and V = e^{(V_max. [S]/K_M)}, while k, V_max and K_M are the kinetic, maxim velocity and Michaelis-Menten constants, respectively. Models proposed in this work have been compared to experimental data, and it may be possible to simulate the starch hydrolysis process by amylases and its scale-up. Results showed that exponential models were more appropriate to use than Michaelis-Menten model for V values higher than 0.3 g/L.min. At a V range lower than 0.3 g/L.min, both models were satisfactory predictives. For starch hydrolysis, the exponential models perceived that, at optimal conditions, the mean yield was 70%. After fermentation, an alcohol yield above 45% was obtained (the theoretical is 51.1%).

Recommended Citation

Curvelo-Santana, José Carlos; Librantz, André Felipe; and Tambourgi, Elias (2009) "Approach Model for Simulation of the Starch Hydrolysis by α-Amylase and Alcohol Production from Manioc Root Starch," Chemical Product and Process Modeling: Vol. 4 : Iss. 4, Article 13.
DOI: 10.2202/1934-2659.1318
Available at: http://www.bepress.com/cppm/vol4/iss4/13