Study on the Properties of Immobilized Biocatalysts with Lipase Activity Produced by Yarrowia lipolytica in Batch Culture.

Three kinds of matrices (calcium alginate, gelatin, and PVA) were employed as supports to immobilize lipases from Y. lipolytica KKP 379 via physical adsorption. The stability of biocatalysts (free and immobilized) was evaluated by measuring the enzyme activity before and after treatment with the method based on the hydrolysis of p-nitrophenyl laurate. Two fractions of enzymes were immobilized: cell-bound (yeast biomass) and extracellular (supernatant). The yield of immobilization and catalytic properties of immobilized lipases were investigated. Satisfactory results for lipolytic activity and biocatalyst stability were obtained for cell-bound enzymes immobilized in alginate (0.38 U g-1 d.m.) and crosslinked gelatin (0.18 U g-1 d.m.). Immobilization of the supernatant was successful only on the alginate (0.026 U g-1 d.m.). After lyophilization, no significant difference was noticed between treated and untreated biocatalysts. Lyophilized catalysts were successfully immobilized in all three matrices, but the process reduced their lipolytic activity probably due to an insufficient amount of water in the reaction solution. [ABSTRACT FROM AUTHOR]