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 a new vacuum evaporation method on chemical and sensory properties of must and wine

A new process for vacuum evaporation was developed where evaporation takes place near the inner surface of a vortex produced by a rotor submerged in the liquid. Contrary to the state of the art the Vortex rotor process does not need a vacuum vessel but the rotating liquid creates a geometrically stable low pressure void surrounded by a vortex stabilized by the equilibrium between centrifugal forces and the pressure difference. First tests with water and sugar solutions at concentrations similar to grape must were conducted to verify the theoretical predictions, test the performance under different conditions and study the effect of various process parameters (Rösti et al 2015).

How small amounts of oxygen introduced during bottling and storage can influence the metabolic fingerprint and SO2 content of white wines

The impact of minute amounts of headspace oxygen on the post-bottling development of wine is generally considered to be very important, since oxygen, packaging and storage conditions can either damage or improve wine quality. This is reflected in the generalised use of inert bottling lines, where the headspace between the white wine and the stopper is filled with an inert gas. This experiment aimed to address some open questions about the chemistry of the interaction between wine and oxygen, crucial for decisions regarding optimal closure. While it is known that similar amounts of oxygen affect different wines to a variable extent, our knowledge of chemistry is not sufficient to construct a predictive method.

Assessing the effect of oak derived aromas on mouthfeel perception in Chardonnay wine

Mouthfeel is an important quality parameter for Chardonnay wines, particularly those aged in oak. While research on mouthfeel has traditionally focused on the impact of non-aromatic compounds, the role of aroma compounds has largely been over looked. However, in wine as well as other food interactions between retronasal aroma and mouthfeel have been noted. The goal of this research was to investigate the impact of wine aroma on the perception of mouthfeel. Because of the importance of oak aging in the development of Chardonnay mouthfeel, the impact of oak aromas on perceived mouthfeel was explored. Aroma compounds associated with oak (ethyl palmitate, eugenol, furfural, isoeugenol, syringaldehyde, vanillin and whiskey lactone) were added to two different Chardonnay wines; one with no oak influence and one fermented in neutral oak. Low and high concentrations of the compounds were added based on concentrations typically found in barrel aged Chardonnay wine.

Ellagitannins and flavano-ellagitannins: concentration ranges in different areas and sensory evaluation

C-Glucosidic ellagitannins, which are the main polyphenolic compounds in oak heartwood, are extracted by wine during aging in oak barrels. Although such maturing of alcoholic beverages in oak barrels is a multi-centennial practice, very little is known on the impact of these ellagitannins on the organoleptic properties of red wine. The objectives of the present investigation were (i) to isolate oak ellagitannins and to hemisynthesize some made-in-wine flavano-ellagitannins, such as acutissimin A; (ii) to analyse their concentration ranges depending on the cultivar area and (iii) to evaluate their sensory impact on the basis of their human threshold concentrations and dose/response relationships in different types of solutions.

Characterization of free and glycosidically bound simple phenols in hybrid grape varieties using liquid chromatography coupled to high resolution mass (q-orbitrap)

Vitis vinifera is one of the most diffused grapevines over the word and it is the raw material for high quality wines production. The availability of more resistant interspecific hybrid vine varieties, developed from crosses between Vitis vinifera and other Vitis species, has generating much interest, also due to the low environmental effect of production. However, hybrid grape wine composition and varietal differences between interspecific hybrids are not well defined. Different studies revealed that wine consumption has health effects due to its high content of antioxidants, as phenolic compounds. In particular, simple phenols are appreciated not only for their physiological health benefits, including antioxidant, anti-inflammatory and cardioprotective effects, but also because they affect wines organoleptic profile and have a significant role in defining their nutritional characteristics.