title: Production and immobilization of enzymes by solid-state fermentation of agroindustrial waste.
abstract: The recovery of by-products from agri-food industry is currently one of the major challenges of biotechnology. Castilla-La Mancha produces around three million tons of waste coming from olive oil and wine industries, both of which have a pivotal role in the economy of this region. For this reason, this study reports on the exploitation of grape skins and olive pomaces for the production of lignocellulosic enzymes, which are able to deconstruct the agroindustrial waste and, therefore, reuse them in future industrial processes. To this end, solid-state fermentation was carried out using two local fungal strains (Aspergillus niger-113 N and Aspergillus fumigatus-3). In some trials, a wheat supplementation with a 1:1 ratio was used to improve the growth conditions, and the particle size of the substrates was altered through milling. Separate fermentations were run and collected after 2, 4, 6, 8, 10 and 15 days to monitor enzymatic activity (xylanase, cellulase, β-glucosidase, pectinase). The highest values were recorded after 10 and 15 days of fermentation. The use of A. niger on unmilled grape skin yielded the best outcomes (47.05 U xylanase/g by-product). The multi-enzymatic extracts obtained were purified, freeze dried, and immobilized on chitosan by adsorption to assess the possible advantages provided by the different techniques.
authors.affiliation: Food Science and Technology, University of Castilla-La Mancha (UCLM), Av. Camilo José Cela 10, Edificio Marie Curie, 13071, Ciudad Real, Spain, s.romosanchez@gmail.com.
authors.forename: Sheila
authors.initials: S
authors.lastname: Romo Sánchez
authors.forename: Irene
authors.initials: I
authors.lastname: Gil Sánchez
authors.forename: María
authors.initials: M
authors.lastname: Arévalo-Villena
authors.forename: Ana
authors.initials: A
authors.lastname: Briones Pérez
mesh_terms: D001232:Aspergillus fumigatus / Q000737:chemistry / Q000201:enzymology / Q000254:growth & development; D001234:Aspergillus niger / Q000737:chemistry / Q000201:enzymology / Q000254:growth & development; D048271:Chitosan / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000096:biosynthesis / Q000737:chemistry; D019649:Food Industry; D007220:Industrial Waste
chemical_list: D004800:Enzymes, Immobilized; D007220:Industrial Waste; D048271:Chitosan