Enhance hydrolytic enzymes production by Aspergillus awamori on supplemented grape pomace

The disposal of grape pomace by wine cellars leads to serious environmental problems. In this work we have evaluated the potential utility of this waste as substrate of fermentation for the production of several hydrolytic enzymes commonly used in the clarification processes in wine cellars and juices industries. Our results have demonstrated that the synthesis of exo-polygalacturonase (exo-PG), xylanase and cellullase by solid state fermentation (SSF) on a mixture of washed grape pomace and orange peels (a natural source of pectin, cellulose and hemicellulose), supplemented with a nutrient solution, increased compared to whole grape pomace. For experiments carried out with suspensions of the same mixed substrates in submerged fermentation (SmF), higher values for pectinase and xylanase were reached but with significant lower exo-PG activity per mL of extract. The activities of these enzymes on mixtures of grape pomace and orange peels, in both SSF and SmF, were similar or even higher to those produced using other agro-industrial wastes, demonstrating therefore its potential utility as an alternative substrate for the production of enzymatic extracts for clarification purposes.

► Grape pomace has an enormous potential to produce hydrolytic enzymes used in clarification processes.
► The production was stimulated by mixing grape pomace with orange peels, natural source of pectin.
► The enzyme synthesis is similar or even higher to those produced by other agro-industrial residues.