Compared esterification kinetics of the lipase from Burkholderia cepacia either free or encapsulated in a silica aerogel

This paper presents an experimental comparison of the kinetics of esterification catalyzed with the lipase from Burkholderia cepacia, either free, or encapsulated in a silica aerogel dried by the supercritical CO2 method. The operational characteristics, in terms of pre-equilibration at given water thermodynamic activity aw, mass of enzyme in the gel, size of aerogel particles, are presented. The kinetic model known as BiBi Ping Pong with inhibition by both substrates has been found to fit relatively well with the experimental results, except when both substrate concentrations were high with the encapsulated enzyme. All kinetics constants were found to be increased by aerogel encapsulation. In particular Vmax was increased by a factor of the order of 10 per mg of enzyme.