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…

Trans-resveratrol concentrations in wines Cabernet Sauvignon from Chile

This study evaluated the levels of trans-resveratrol in commercial wines made from Cabernet Sauvignon grapes from different valleys of Chile stilbenes. The Cabernet Sauvignon is the most planted variety in Chile, being 38% of the total vineyard country. Chile is the fourth largest wine exporter in the world, so it is important to evaluate the Cabernet-Sauvignon wines in their concentration levels of trans-resveratrol and its relation to the benefits provided to human health in moderate consumption. Evaluation comprises commercial wines from different valleys of Chile and its relationship with climatic characteristics, soil and vineyard handling.

On the losses of dissolved CO2 during champagne aging

A misconception lingers in the minds of some wine consumers that Champagne wines don’t age. It’s largely a myth, certainly as far as the best cuvees are concerned. Actually, during the so-called autolysis period of time (in the closed bottle, after the “prise de mousse”), complex chemical reactions take place when the wine remains in contact with the dead yeast cells, which progressively bring complex and very much sought-after aromas to champagne. Nevertheless, despite their remarkable impermeability to liquid and air, caps or natural cork stoppers used to cork the bottles are not 100% hermetic with regard to gas transfers. Gas species therefore very slowly diffuse through the cap or cork stopper, along their respective inverse partial pressure. After the “prise de mousse”, because the partial pressure of CO2 in the bottleneck reaches up to 6 bars (at 12 °C), gaseous CO2 progressively diffuse from the bottle to the ambient air
(where the partial pressure of gaseous CO2 is only of order of 0,0004 bar).

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].

Study of the content of amino acids and biogenic amines in sparkling red wines

The production of red sparkling wines is lower in Spain in comparison with the winemaking of white or rosé sparkling wines. In red sparkling wine processing it is essential to obtain suitable base wines that should have moderate alcohol content, high acidity, good color values, an adequate mouth-feel and a sweet tannin. Grapes for sparkling wine production have to be harvested at low maturity stages, with lower alcohol contents and higher acidities, which will that the phenolic maturity of the grapes is also low, showing green tannins. This paper analyses different treatments in order to minimize these inconveniences: cold maceration-prefermentation and delestage to elaborate the grapes with lower maturity, must nanofiltration, and the partial osmosis of the wines made from grapes with an adequate maturity degree.

Microbial stabilization of wines using innovative coiled UV-C reactor process: impact on chemical and organoleptic proprieties

For several years, numerous studies aimed at limiting the use of SO2 in wines (thermal treatments, pulsed electric fields, microwaves …). Processes must be able to preserve the organoleptic qualities of wines with low energy consumption. In this context, ultraviolet radiations (UV-C), at 254 nm, are well known for their germicidal proprieties. In order to inactivate microorganisms in grape juice and wine without affecting the quality of the product, efficiency of UV-C treatment process should be optimized.