Michaelis-Menten Kinetic Parameters of Coconut Coir Enzymatic Hydrolysis

The limitation of fossil oil reserves and environmental pollution has been current problems that need to be solved. Biofuels such as ethanol can be alternative energy source that can reduce demand on fossil fuel and environmental problem. Food wastes such as coconut coirs are abundant and contain carbohydrate which can be used as the substrate for biofuel production. Pretreatment and hydrolysis are important stages which have to be applied on such lignocellulose materials before fermentation process to produce biofuel. This article presents Michaelis-Menten kinetic parameters for coconut coir enzymatic hydrolysis. Coconut coirs collected from several local markets in Surabaya were subjected to alkaline pretreatment using 11% sodium hydroxide solution at 121oC. Hydrolysis steps were carried out using commercial enzymes at various initial substrate concentrations. The hydrolysis conditions were at 50oC and pH 4.8. The concentrations of reducing sugar produced in the reactions were measured at certain time intervals. Initial rate of reactions of each reaction batch were then determined. Finally, kinetic parameters of Michaelis-Menten model for enzymatic reaction were determined by fitting the initial rate of reactions and initial substrate concentration data. From nonlinear fitting, the maximum reaction rate (Vm) is 4.9´104 1/h and the value of KM is 4,195 mg/L.