Optimización de la producción heteróloga de la enzima α-galactosidasa de "Saccharomyces cerevisiae" a partir de residuos agroindustriales

Abstract

α-galactosidases are enzymes that act on galactosides present in many plants that are destined to the elaboration of food and feed. It is for this reason that the use of the catalytic activity of these enzymes is of great interest in many biotechnological applications, especially those directed in the food industry to the degradation of oligosaccharides derived from raffinose (RFOs). In this Doctoral Thesis, studies of enzymatic characterization and systems of heterologous production of the α-galactosidase of Saccharomyces cerevisiae are proposed to evaluate the possibilities of its use in industrial production processes. Enzyme belongs to Group 1 of α-galactosidases according to the action on synthetic galactomano-oligosaccharides and has a strong resistance to acid-neutral proteases, an industrial desirable quality. Genetic improvement of a strain of S. cerevisiae and the use of an expression system in Kluyveromyces lactis allowed the production of the enzyme from agroindustrial residues of difficult recycling such as beet molasses and whey. The Response Surface Methodology (RSM) was used for statistical optimization of enzyme production using conventional and sustainable alternative culture media, reaching the highest results described so far expressed in terms of extracellular α-galactosidase activity. Finally, given the current interest in the reuse and valorization of this type of agroindustrial residues, studies of enzymatic immobilization were carried out using enzymatic preparations from recombinant strains. The design of different immobilization strategies allowed to increase the operational stability of different derivatives of the enzyme, which represent an additional advantage according to the needs of the industrial use.