Characterization, performance, and applications of a yeast surface display-based biocatalyst

Abstract

This work demonstrates the efficacy and cost effectiveness of yeast surface display (YSD) as a method for producing and purifying enzyme catalysts. Lipase B from Candida antarctica (CalB) and lipase from Photobacterium lipolyticum sp. M37 (M37L) were individually displayed on the surface of yeasts via fusion with alpha-agglutinin. The enzyme is produced, purified, and immobilized in a single step. The population expressing the enzyme was quantified by flow cytometry. After lyophilization, the hydrolytic activity of the biocatalyst was assayed with p-nitrophenyl butyrate and p-nitrophenyl palmitate substrates. Esterification reactions involving octanoic acid and either butanol or octanol were used to evaluate esterification activity. The lyophilized YSD biocatalyst hydrolytic activity matched or exceeded commercial lipase (Novozym 435) immobilized on acrylic resin at equal catalyst loading, and achieved esterification levels 10–50% that of Novozyme 435. Factoring in the cost of production, the YSD biocatalyst represents a considerable savings over traditionally prepared and purchased enzyme catalysts. This promises to significantly expand the catalytic applications of immobilized lipases, and immobilized enzymes more generally, in commercial processes.