Kinetic Study of Ethyl Hexanoate Synthesis Using Surface Coated Lipase from Candida Rugosa

Kinetics of lipase-catalyzed esterification of hexanoic acid and ethyl alcohol using the solvent-free system, surface coated lipase from Candida rugosa, had been studied. The effect of various parameters such as reaction time, reaction temperature, reaction kinetics, water removal and feasibility of solvent-free system had been focused. Candida Rugosa lipase was more effective than other lipases when ethyl hexanoate was synthesized in n-hexane. The highest esterification yield after ۷۲ h (۹۳ %) was achieved at a pH of ۵.۲ and the esterification yield was reduced to ۷۳% at pH ۴.۰. The values of the apparent kinetic parameters were computed as Vmax= ۰.۱۴۶ μmol/min/mg enzyme; KM, Acid = ۰.۲۹۶ M; KM, Alcohol = ۰.۱۳۸۸ M; Ki, Acid = ۰.۴۰ M; and Ki, Alcohol = ۰.۳۰۹ M. The reaction rate could be described in terms of the Michaelis–Menten equation with a Ping-Pong Bi-Bi mechanism and competitive inhibition by both the substrates.

کلیدواژه ها:

Candida rugosa ، ethyl hexanoate ، surface coated lipase ، Transesterification ، kinetic studies