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…

Anthropogenic factors in modulations of fungal populations from grapes to wines and their repercussions on wine characteristics

The effects of anthropogenic activities on vineyard (different plant protections) and in winery
(pressing/clarification step, addition of sulfur dioxide) on fungal populations from grape to wine were studied. The studied anthropogenic activities modify the fungal diversity. Thus, lower biodiversity of grapes from organic modality was measured for the three vintages considered compared to biodiversity from ecophyto modality and conventional modality. The pressing / clarification steps strongly modify fungal populations and the influence of the winery flora is highlighted.

Reduction of herbaceous aromas by wine lactic acid bacteria mediated degradation of volatile aldehydes

Consumers typically prefer wines with floral and fruity aromas over those presenting green-pepper, vegetal or herbaceous notes. Pyrazines have been identified as causatives for herbaceous notes in wines, especially Bordeaux reds. However, pyrazines are not universally responsible for herbaceousness, and several other wine volatile compounds are known to produce distinct vegetal/herbaceous aromas in wines. Specifically, volatile aldehydes elicit sensations of herbaceousness or grassiness and have been described in wines well above their perception thresholds.

On the losses of dissolved CO2 from laser-etched champagne glasses under standard tasting conditions

Under standard champagne tasting conditions, the complex interplay between the level of dissolved CO2 found in champagne, its temperature, the glass shape, and the bubbling rate, definitely impacts champagne tasting by modifying the neuro-physico-chemical mechanisms responsible for aroma release and flavor perception. Based on theoretical principles combining heterogeneous bubble nucleation, ascending bubble dynamics and mass transfer equations, a global model is proposed (depending on various parameters of both the wine and the glass itself), which quantitatively provides the progressive losses of dissolved CO2 from laser-etched champagne glasses.

Oligosaccharides in red wines: could their structure and composition be influenced by the grape-growing

Oligosaccharides have only recently been characterized in wine, and the information on composition and content is still limited. In wine, these molecules are mainly natural byproducts of the degradation of grape berry cell wall polysaccharides. Wine oligosaccharides present several physicochemical properties, being one relevant factor linked to the astringency perception of wines (1,2). A terroir can be defined as a grouping of homogeneous environmental units based on the typicality of the products obtained. This notion is particularly associated with wine, being the climate and the soil two of the major elements of terroir concept.

Effect of post-harvest ozone treatments on the skin phenolic composition and extractability of red winegrapes cv Nebbiolo and Barbera

Wine industry is looking forward for innovative, safe and eco-friendly antimicrobial products allowing the reduction of chemical treatments in the grape defense and the winemaking process that can affect negatively the quality of the product. Ozone has been tested in food industry giving good results in preventing fungi and bacteria growth on a wide spectrum of vegetables and fruits, due to its oxidant activity and ability to attack numerous cellular constituents. Ozone leaves no chemical residues on the food surface, decomposing itself rapidly in oxygen. Gaseous ozone has been already tested for table grapes storage and on wine grapes during withering.