The Universitat Rovira i Virgili, in collaboration with the research institutions affiliated to the Campus of International Excellence Southern Catalonia (CEICS), is launching the Martí i Franquès research grants programme, a public-private cooperation designed to attract highly talented doctoral students and postdoctoral researchers to work on exciting research projects.
This programme honours the scientist Antoni Martí i Franquès (Altafulla, 1750 Tarragona, 1832), who made remarkable contributions not only to the fields of biology, physics and chemistry, but also to the economic development of Southern Catalonia.
He was the first scientist to accurately establish the composition of air.
SPECIFIC POSITION OFFER 2020PMF-PIPF-32
This project aims to advance on the knowledge about the implications of laccase enzyme activity in wine composition and quality.
Laccase is a multi-copper oxidase (MCOs) that belongs to a protein superfamily of enzymes which oxidize the substrate at a mononuclear copper center T1.
This enzyme is released by the fungi Botrytis cinerea when grows in grape berries. This fungal disease, known as grey rot is probably the worst plague that affects grape production.
This enzyme causes great problems of color originating browning in white wines and oxidasic haze in red wines because it oxidizes phenolic compounds.
This fungal disease represents each year great economic losses for wine industry. The main objective of this project is acquiring enough knowledge about this enzyme in order to mitigate the undesirable action that laccase exert in the oenological industry, enabling a reduction in the use of SO2.
It is also aimed to evaluate the possible favorable effects that laccase can exert on wine under the point of view of quality (reduction of astringency in red wines, hyperoxidation to stabilize the color of white wines).
This project will first address the isolation and purification of laccase from Botrytis cinerea to obtain enough amount for the following objectives.
Next, the characterization of the laccase of Botrytis cinerea will be performed. To do this, their molecular masses and isoelectric points will be determined by electrophoretic techniques, and their kinetic characteristics will be determined according to the Michaelis-Menten model using syringaldazine as the substrate of the reaction and also developing another chemical model to reproduce wine browning in a synthetic medium.
Subsequently, the study of the kinetics of the reaction of laccase with various substrates of interest will be performed by determining the kinetics of oxygen consumption in real grape juice and also in a model medium.
Finally, the inhibitory effect on laccase of enological tannins and glutathione as possible alternatives to reduce sulfur dioxide doses will be studied.
Required Research Experiences