Cocoa shell for the production of endoglucanase by Penicillium roqueforti atcc 10110 in solid state fermentation and biochemical properties

This paper aims to evaluate the use of the cocoa shell residue as an alternative substrate for the production of endoglucanase by Penicillium roqueforti ATCC 10110 in solid state fermentation. In order to do so, the process was optimized and biochemical properties were investigated. The Box-Behnken design was utilized for verify the parameters: incubation time, water activity and fermentation temperature were optimized by response surface methodology, in order to increase the yield of enzymatic activity coupled with an economic process. Temperature, pH, different ions and solvents stability and determination of kinetic parameters were also verified. The maximum activity was 0.89 U/g under the conditions of fermentation time, water activity and incubation temperature were of 72h, 0.964Aw and 30°C, respectively. A higher endoglucanase activity at pH 5 and temperature 50 °C was achieved during the reaction, were stable at pH in the range 5 to 7 and temperatures ≤ 70°C. The addition of the Mg2+, Cu2+, Co2+ ions, the trolox and SDS compounds to the crude extract resulted in increased enzymatic activity. The dichloromethane and hexane behaved as endoglucanase activators, increasing the activity of the enzyme in 5.42 and 1.18%, respectively. kinetic parameters Km and Vmax were determined using carboxymethylcellulose as substrate, with values of 1.17 mg/mL and 0.90 mg/mL/min, respectively.

Keywords: Box-Behnken design, Stability, Kinetic parameters, Endoglucanase.