Macrowine 2021
IVES 9 IVES Conference Series 9 Proteomic and activity characterization of exocellular laccases from three Botrytis cinerea strains

Proteomic and activity characterization of exocellular laccases from three Botrytis cinerea strains

Abstract

Botrytis cinerea is a fungus that causes common infection in grapes and other fruits. In winemaking, its presence can be both considered desirable in the case of noble rot infection or undesirable when grey rot is developed. This fungus produces an extracellular enzyme known as laccase which is able to cause oxidation of phenolic compounds present in must and wine, causing most of the times a decrease in its quality and problems during the winemaking process [1]. Material and methods: Three B. cinerea strains (B0510, VA612 and RM344) were selected and grown in a liquid medium adapted from one previously described [2]. The enzyme was isolated by tangential ultrafiltration of the culture medium using a QuixStand system equipped with a 30 KDa filtration membrane. The purity of the isolated enzymes was checked using SDS-PAGE. The characteristics (molecular weight, % of glycosylation, specific activity, activity in function of pH of the enzyme isolated from each strain were studied with ABTS as a substrate. Results: The enzymes isolated from the three strains showed the same molecular weight, 97 KDa, in good agreement with the molecular weight previously determined for B. cinerea laccase using SDS-PAGE [2]. The percentage of glycosylation was high, being estimated in 70% on weight, also similar to that described by other authors [3]. Despite similar physical characteristics of the enzymes obtained from different strains, their activity were quite different. The enzymes isolated from B0510 and VA612 strains showed similar specific activity for ABTS oxidation, being 0.3 and 0.21 mM for their Km and their Vmax were 1.28 and 1.45 mM/min per milligram of enzyme respectively. The activity for RM344 enzyme was found much lower, with values of 0.78 mM for Km and 0.13 mM/min per milligram of enzyme for Vmax. The enzyme isolated from the B0510 strain presented its highest activity at pH 2.9 while VA612 and RM344 enzymes showed the maximum activity at pH 3.3. All these values were quite lower compared to previously measured by other authors [4-6]. Those differences in the enzyme activity may be related with differences in the active center of the enzyme and could have important consequences for the winemaking process depending on the strains of the B. cinerea strain involved in the infection of grapes.

[1]P. Ribéreau-Gayon, Y. Glories, A. Maujean, D. Dubourdieu, Handbook of Enology, Volume 2: The chemistry of Wine Stabilization and Treatments, John Wiley & Sons, Ltd, 2000. [2]D. Slomczynski, J.P. Nakas, S.W. Tanenbaum, Applied and Environmental Microbiology, 61 (1995) 907. [3]C. THURSTON, Microbiology-Sgm, 140 (1994) 19. [4]I. MARBACH, E. HAREL, A. MAYER, Phytochemistry, 23 (1984) 2713. [5]I. MARBACH, E. HAREL, A. MAYER, Phytochemistry, 22 (1983) 1535. [6]M. Dubernet, P. Ribereau-Gayon, H.R. Lerner, E. Harel, A.M. Mayer, Phytochemistry, 16 (1977) 191.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Cédric Saucier*, Anne-Sophie Walker, Christiane Auclair, François Garcia, Francois-Xavier Sauvage, Jullien Drone, Natalia Quijada-Morin, Patrick Chemardin

*Université de Montpellier

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Moscatel vine-shoot extracts as grapevine biostimulant to increase the varietal aroma of Airén wines

There is a growing interest in the exploitation of vine-shoots waste, since they are often left or burned. Sánchez-Gómez et al. [1] have shown that vines-shoots aqueous extracts have significant contents of bioactive compounds, among which several polyphenols and volatiles are highlighted. Recent studied had demonstrated that the chemical composition of vine-shoots is enhanced when vine-shoots are toasted
[2,3]. The application of vegetable products in the vineyards has led to significant changes towards a more “Sustainable Viticulture”. An innovative foliar application for Airén vine-shoot extracts have been carried out to the vineyard. It has been shown that they act as grape biostimulants, improving certain wine quality characteristics [4].

Colour assessment of port wines using colorimetric and spectrophotometric methods

Colour is an important quality parameter in wines and is the result of a complex mixture of pigments
(including anthocyanins and their derivatives, quinones, xanthyllium compounds, etc.). Red wine colour changes over time as pigments react between themselves and with other wine macromolecules
(particularly polyphenols). During wine tasting, colour is normally assessed on the outer rim of the wine profile in a tilted glass, since most wines are too opaque to be analysed in the middle of the glass. Therefore, depending on the depth of observation considered, the perception of wine colour can be different.

Influence of preflowering basal leaf removal on aromatic composition of cv. Tempranillo wine from semiarid climate (Extremadura Western Spain)

Abstract In this work the effects of early leaf removal performed manually at preflowering phenological stage, on the volatile composition of Tempranillo (Vitis vinifera L.) wines were studied. From 2009-2011 vintages 34 wine volatile compounds were identified and quantified by gas chromatography-mass spectrometry (GC-MS) where early leaf removal only modified 25 of them. The total C6 compounds, acetates and volatiles acids (with exception of isobutyric acid) were affected by defoliation, whereas alcohols and esters showed a minor effect. Furthermore the vintage effect also was shown.

Enological evaluation of the attitude of the grapevine fumin to give varietal wines

Initiatives have been ongoing in recent years to safeguard biodiversity in the oenological sector via a process of enhancement of ancient varieties, under a pressure of a market strongly oriented towards production deriving from native vines of specific geographical zones. In that sense, Aosta Valley
(Italy) has raised the need to preserve and characterize its minority vine varieties which have the potentiality to give varietal wines. Fumin represents the 7% of the production of the region with 16 hectares of vineyards and 753 hectolitres of derived wine. Due to its large phenolic potential, strong astringency and deep colour, it has long been, and is still today, assembled or blended with other varieties as occurs, for example, for the Torrette.

Characterization of commercial enological tannins and its effect on human saliva diffusion

Commercial oenological tannins (TECs) are widely used in the wine industry. TECs are rich in condensed tannins, hydrolyzable tannins or a mixture of both. Wine grapes are a important source of proanthocyanidins or condensed tannins while oak wood possess a high concentration of hydrolyzable tannins (Obreque-Slier et al., 2009). TECs contribute with the antioxidant capacity of wine, catalyze oxide-reduction reactions and participate in the removal of sulfur compounds and metals.