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…

Effects of bottle closure type on sensory characteristics of Chasselas wines

Several winemaking operations, such as filtration, pumping, and racking, are known to potentially facilitate the incorporation of atmospheric O2 into the wine. Control of grape must oxidation is one key aspect in the management of white wine aroma expression, color stability and shelf-life extension. On the one hand, controlled must oxidation may help to remove highly reactive phenolic compounds, which otherwise could contribute to premature oxidation. And on the other hand, in certain cases of extreme protection of the must from O2 (e.g. pressing under inert atmosphere), it can help to preserve varietal aromas and natural must antioxidants.

Oxygen consumption by diferent oenological tanins in a model wine solution

INTRODUCTION: Oenological tannins are widely used in winemaking to improve some characteristics of wines [1] being the antioxidant properties probably one of the main reasons [2]. However, commercial tannins have different botanical sources and chemical composition [3] which probably determines different antioxidant potential. There are some few references about the antioxidant properties of commercial tannins [4] but none of them have really measured the direct oxygen consumption by them. The aim of this work was to measure the kinetics of oxygen consumption by different commercial tannins in order to determine their real capacities to protect wine against oxygen. MATERIAL AND METHODS: 4 different commercial tannins were used: T1: condensed tannin from grape seeds, T2: gallotannin from chinese gallnuts, T3: ellagitannin from oak and T4: tannin from quebracho containing condensed tannins and ellagitannins.

Maturation of Agiorgitiko (Vitis vinifera) red wine on its wine lees: Impact on its phenolic composition

Maturation of wine on lees (often referred as sur lie) is a common practice applied by many winemakers around the world. In the past this method was applied mainly on white and/or sparkling wine production but recently also to red wine production. In our experiment, we matured red wine on wine lees of two origins: a) Light wine lees, collected after the completion of the alcoholic fermentation, b) Heavy lees, collected after the completion of the malolactic fermentation. The lees were free of off-odors and were added in the red wine in percentage 3% and 8%, simulating common winemaking addition. The maturation lasted in total six months and samples were collected for analysis after one, three and six months. During storage the lees were stirred.

The role of tomato juice serum in malolactic fermentation in wine

Introduction: Malolactic fermentation (MLF) is a common process in winemaking to reduce wine acidity, maintain microbial stability and modify wine aroma. However, successful MLF is often hampered by their sluggish or stuck activity of malolactic bacteria (MLB) which may be caused by nutrient deficiency, especially when MLB are inoculated after alcoholic fermentation (Alexandre et al., 2004; Lerm et al., 2010). Identification and characterization of essential nutrients and growth factors for MLB allows for production of highly efficient nutrient supplements for MLF.

Monitoring of Pesticide Residues from Vine to Wine

Those previous years, pesticides are often brought to the forefront by media. Questions arose about their toxicity for growers and consumers. Even if a downward trend is underway, the use of pesticides is required to ensure steady quality and quantity of harvests. A large number of active ingredients are authorized but regarding viticulture, mainly insecticides and fungicides are applied, to control pests and diseases and to increase crop yield. Some phytosanitary products, principally fungicides, applied close to the harvest date may frequently be detected in wines.