title: Profiling the Hydrolysis of Isolated Grape Berry Skin Cell Walls by Purified Enzymes.
abstract: The unraveling of crushed grapes by maceration enzymes during winemaking is difficult to study because of the complex and rather undefined nature of both the substrate and the enzyme preparations. In this study we simplified both the substrate, by using isolated grape skin cell walls, and the enzyme preparations, by using purified enzymes in buffered conditions, to carefully follow the impact of the individual and combined enzymes on the grape skin cell walls. By using cell wall profiling techniques we could monitor the compositional changes in the grape cell wall polymers due to enzyme activity. Extensive enzymatic hydrolysis, achieved with a preparation of pectinases or pectinases combined with cellulase or hemicellulase enzymes, completely removed or drastically reduced levels of pectin polymers, whereas less extensive hydrolysis only opened up the cell wall structure and allowed extraction of polymers from within the cell wall layers. Synergistic enzyme activity was detectable as well as indications of specific cell wall polymer associations.
authors: Institute for Wine Biotechnology, Department of Viticulture and Oenology, Faculty of AgriSciences, Stellenbosch University , Matieland 7602, South Africa.
authors: Anscha J J
authors: AJ
authors: Zietsman
authors: Institute for Wine Biotechnology, Department of Viticulture and Oenology, Faculty of AgriSciences, Stellenbosch University , Matieland 7602, South Africa.
authors: John P
authors: JP
authors: Moore
authors: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen , DK-1001 Copenhagen, Denmark.
authors: Jonatan U
authors: JU
authors: Fangel
authors: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen , DK-1001 Copenhagen, Denmark.
authors: William G T
authors: WG
authors: Willats
authors: Institute for Wine Biotechnology, Department of Viticulture and Oenology, Faculty of AgriSciences, Stellenbosch University , Matieland 7602, South Africa.
authors: Melané A
authors: MA
authors: Vivier
mesh_terms: D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism*; D002480:Cellulase / Q000378:metabolism; D005638:Fruit / Q000378:metabolism* / Q000648:ultrastructure; D006026:Glycoside Hydrolases / Q000378:metabolism; D006868:Hydrolysis; D010368:Pectins / Q000032:analysis; D011096:Polygalacturonase / Q000378:metabolism; D011108:Polymers / Q000032:analysis; D046888:Tissue Array Analysis; D027843:Vitis
chemical_list: D011108:Polymers; D010368:Pectins; D006026:Glycoside Hydrolases; C023305:hemicellulase; D011096:Polygalacturonase; D002480:Cellulase
keywords: cell wall polymer; enzymes; grape berry skin