Macrowine 2021
IVES 9 IVES Conference Series 9 Ochratoxin a degradation by Botrytis cinerea laccase: effect of oenological factors and redox mediators

Ochratoxin a degradation by Botrytis cinerea laccase: effect of oenological factors and redox mediators

Abstract

AIM: This study evaluates the effect of different oenological factors and natural mediators on the degradation of Ochratoxin A (OTA) using Botrytis cinerea laccase. Because of its risk to human health, different detoxification techniques have been developed in various kinds of foodstuffs. The use of fungal or bacterial laccases is a biological method to decrease the OTA concentration [1, 2]. Laccases can oxidize a wide range of substrates, some of which cannot be oxidized directly by these enzymes and require the use of redox mediators [3]. Due to this, several natural mediators present in wine and different SO2 and ethanol concentrations were tested in the current work.

METHODS: The ability of laccase to degrade OTA was studied by incubation of the enzyme in acetate buffer pH 4.0 and model wine, with OTA and mediators at 28 ºC during 24 h. To determine the impact of SO2 and ethanol on the OTA degradation caused by laccase, different concentrations of SO2 (10, 20 and 30 mg/L) and ethanol (5, 10 and 15% v/v) were used. The quantification of this mycotoxin was carried out in a HPLC-QTOF-MS system.

RESULTS: Under these conditions, OTA cannot be oxidized directly by laccase from Botrytis cinerea and the use of redox mediators is required. Among natural mediators tested, (-)-epicatechin and (+)-catechin were the phenolic compounds with higher impact on the biodegradation of this mycotoxin, achieving a decrease of OTA concentration over 50%. The degradation of OTA was completely inhibed by 30 mg of SO2/L,  while 20 mg of SO2/L reduced lacasse activity by a half and 10 mg of SO2/L hardly caused any effect on the biodegradation of this mycotoxin. A concentration of 15% of ethanol led to a 50% reduction in the activity of laccase over OTA. 

CONCLUSIONS

These preliminary results may be a first step in finding biological alternative strategies to eliminate undesirable substances such as mycotoxins (OTA) present in wine.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

osé Pérez-Navarro

Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, Av. Camilo José Cela 10, 13071 Ciudad Real, Spain. Higher Technical School of Agronomic Engineering, University of Castilla-La Mancha, Ronda de Calatrava 7, 13071 Ciudad Real, Spain.,Tania, PANIAGUA MARTÍNEZ, Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, Av. Camilo José Cela, 10, 13071 Ciudad Real, Spain. Pol, GIMÉNEZ, Faculty of Oenology, University of Rovira I Virgili, C/Marcel.li Domingo s/n, 43007 Tarragona, Spain. Joan Miquel, CANALS, Faculty of Oenology, University of Rovira I Virgili, C/Marcel.li Domingo s/n, 43007 Tarragona, Spain. Fernando, ZAMORA, Faculty of Oenology, University of Rovira I Virgili, C/Marcel.li Domingo s/n, 43007 Tarragona, Spain. Sergio, GÓMEZ-ALONSO, Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, Av. Camilo José Cela 10, 13071 Ciudad Real, Spain. Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, Av. Camilo José Cela, 10, 13071 Ciudad Real, Spain.

Contact the author

Keywords

mycotoxin, enzyme, biodetoxification, fungi, SO2, ethanol

Citation

Related articles…

Modeling island and coastal vineyards potential in the context of climate change

Climate change impacts regional and local climates, which in turn affects the world’s wine regions. In the short term, these modifications rises issues about maintaining quality and style of wine, and in a longer term about the suitability of grape varieties and the sustainability of traditional wine regions. Thus, adaptation to climate change represents a major challenge for viticulture. In this context, island and coastal vineyards could become coveted areas due to their specific climatic conditions. In regions subject to warming, the proximity of the sea can moderate extremes temperatures, which could be an advantage for wine. However, coastal and island areas are particular prized spaces and subject to multiple pressures that make the establishment or extension of viticulture complex.
In this perspective, it seems relevant to assess the potentialities of coastal and island areas for viticulture. This contribution will present a spatial optimization model that tends to characterize most suitable agroclimatic patterns in historical or emerging vineyards according to different scenarios. Thanks to an in-depth bibliography a global inventory of coastal and insular vineyards on a worldwide scale has been realized. Relevant criteria have been identified to describe the specificities of these vineyards. They are used as input data in the optimization process, which will optimize some objectives and spatial aspects. According to a predefined scenario, the objectives are set in three main categories associated with climatic characteristics, vineyards characteristics and management strategies. At the end of this optimization process, a series of maps presents the different spatial configurations that maximize the scenario objectives.

Assessing the relationship between cordon strangulation, dieback, and fungal trunk disease symptom expression

Grapevine trunk diseases including Eutypa dieback are a major factor in the decline of vineyards and may lead to loss of productivity, reduced income, and premature reworking or replanting. Several studies have yielded results indicating that vines may be more likely to express symptoms of vascular disease if their health is already compromised by stress. In Australia and many other wine-growing regions it is a common practice for canes to be wrapped tightly around the cordon wire during the establishment of permanent cordon arms. It is likely that this practice may have a negative effect on health and longevity, as older cordons that have been trained in this manner often display signs of decay and dieback, with the wire often visibly embedded within the wood of the cordon. It is possible that adopting a training method which avoids constriction of the vasculature of the cordon may help to limit the onset of vascular disease symptom expression. A survey was conducted during the spring of two consecutive growing seasons on vineyards in South Australia displaying symptoms of Eutypa lata infection when symptomless shoots were 50–100 cm long. Vines were assessed as follows: (i) the proportion of cordon exhibiting dieback was rated using a 0–100% scale; (ii) the proportion of canopy exhibiting foliar symptoms of Eutypa dieback was rated using a 0–100% scale; (iii) the severity of strangulation was rated using a 0–4 point scale. Images were also taken of each vine for the purpose of measuring plant area index (PAI) using the VitiCanopy App. The goal of the survey was to determine if and to what extent any correlation exists between severity of strangulation and cordon dieback, in addition to Eutypa dieback foliar symptom expression.

austrianvineyards.com: online viewer of all designations of Austrian wine

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.

Making sense of available information for climate change adaptation and building resilience into wine production systems across the world

Effects of climate change on viticulture systems and winemaking processes are being felt across the world. The IPCC 6thAssessment Report concluded widespread and rapid changes have occurred, the scale of recent changes being unprecedented over many centuries to many thousands of years. These changes will continue under all emission scenarios considered, including increases in frequency and intensity of hot extremes, heatwaves, heavy precipitation and droughts. Wine companies need tools and models allowing to peer into the future and identify the moment for intervention and measures for mitigation and/or avoidance. Previously, we presented conceptual guidelines for a 5-stage framework for defining adaptation strategies for wine businesses. That framework allows for direct comparison of different solutions to mitigate perceived climate change risks. Recent global climatic evolution and multiple reports of severe events since then (smoke taint, heatwave and droughts, frost, hail and floods, rising sea levels) imply urgency in providing effective tools to tackle the multiple perceived risks. A coordinated drive towards a higher level of resilience is therefore required. Recent publications such as the Australian Wine Future Climate Atlas and results from projects such as H2020 MED-GOLD inform on expected climate change impacts to the wine sector, foreseeing the climate to expect at regional and vineyard scale in coming decades. We present examples of practical application of the Climate Change Adaptation Framework (CCAF) to impacts affecting wine production in two wine regions: Barossa (Australia) and Douro (Portugal). We demonstrate feasibility of the framework for climate adaptation from available data and tools to estimate historical climate-induced profitability loss, to project it in the future and to identify critical moments when disruptions may occur if timely measures are not implemented. Finally, we discuss adaptation measures and respective timeframes for successful mitigation of disruptive risk while enhancing resilience of wine systems.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares