terclim by ICS banner
IVES 9 IVES Conference Series 9 OTA DEGRADATION BY BACTERIAL LACCASEST

OTA DEGRADATION BY BACTERIAL LACCASEST

Abstract

Laccases from lactic acid bacteria (LAB) are described as multicopper oxidase enzymes with copper union sites. Among their applications, phenolic compounds’ oxidation and biogenic amines’ degrada-tion, have been described. Besides, the role of LAB in the toxicity reduction of ochratoxin A (OTA) has been reported (Fuchs et al., 2008; Luz et al., 2018). Fungal laccases, but not bacterial laccases, have been screened for OTA and mycotoxins’ degradation (Loi et al., 2018). OTA is a mycotoxin produced by some fungal species, such as Penicillium and Aspergillus sp., which infect grape bunches used for winemaking. OTA degradation is paramount given that it has been described as human-health harmful according to EFSA.

The work aimed to evaluate the OTA degrading capacity of three heterologous LAB laccases expressed in E. coli. The experimental procedure consisted on testing bacterial laccases from L. lactis, L. paracasei and P. parvulus in acetate buffer pH 4 with or without CuSO4 and OTA in presence and absence of several concentrations of epicatequin and complete polyphenolic extracts from red and white wine as media-tors. Degradation of OTA was followed and quantified by analyzing samples with HPLC-QToF-MS.

According to the results, OTA degradation in the reaction buffer with copper was at least three times higher than without copper. In addition, 0.75 mM epicatequin was the optimum concentration to obtain the highest OTA degradation with L. paracasei laccase (78%). Then, P. parvulus and L. lactis laccases were tested at this concentration, averaging 70% degradation. Finally, mean values of 40% and 10% OTA de-gradation were revealed when using polyphenolic extracts from red and white wine, respectively, for the three laccases. The application of these LAB laccases on OTA degradation in real wine needs to be further explored.

 

1. Fuchs S., et al. (2008). Food Chem Toxicol; 46:1398-1407.
2. Loi M., et al. (2018). Food Control; 90: 401-406.
3. Luz C., et al. (2018). Food Chem Toxicol; 112: 60-66.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Isaac Monroy¹, Isabel Pardo¹, Sergi Ferrer¹, José Pérez-Navarro², Sergio Gómez-Alonso²

1. ENOLAB, Institute BIOTECMED and Microbiology and Ecology Dept, University of Valencia
2. IRICA, University of Castilla-La Mancha

Contact the author*

Keywords

Ochratoxin A reduction, lactic acid bacteria laccases, polyphenolic compounds, redox media-tors

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

SENSORY PROPERTIES IMPORTANT TO AUSTRALIAN FINE WINE CONSUMER SEGMENT PERCEPTION OF CHARDONNAY WINE COMPLEXITY AND PREFERENCE

Wine complexity is considered a multidimensional yet equivocal sensory percept. This project uncovered sensory attributes Australian Chardonnay wine consumers associate with Chardonnay wine complexity and correlations between expert and consumer perceived wine complexity and preference. A wine consumer test examined 6 Australian Chardonnay wines of three complexity levels designated low (LC1&2), medium (MC1&2), and high (HC1&2) by an expert panel (n = 8) using a benchtop sensory task. Consumers (n = 81) rated their perceived liking using a 9-point hedonic scale; wine complexity with a 5-point scale anchored “low”, “low-medium”, “medium”, “medium-high”, and “high” and lastly, profiled the wines using Rate-All-That-Apply (RATA). Psychographic segmentation with the Fine Wine Instrument (FWI) generated three segments; Wine Enthusiasts (WE n=29), Aspirants (ASP n=40) and No- Frills (NF n=12).

FACTORS AFFECTING QUERCETIN SOLUBILITY IN SANGIOVESE RED WINE: FIRST RESULTS

Quercetin (Q) is present in grape in form of glycosides and as aglycone. These compounds are extracted from grape skins during winemaking. In wines, following the hydrolysis reactions, the amount of quercetin aglycon can exceed its solubility value. Unfortunately, a threshold solubility concentration for quercetin in wine is not easy to determine because it depends on wine matrix (Gambuti et al., 2020).

DO MICROPLASTICS IN VINEYARD SOIL AFFECT THE BIOAVAILABILITY OF VINE NUTRITION?

Microplastics can alter physicochemical and biogeochemical processes in the soil, but whether these changes have further effects on soil fertility, and if so, whether these effects vary depending on the type of soil in the vineyard and the type of plastic used in the vineyard. Knowing what types of plastics are currently used in vineyards in Slovenian viticultural regions as strings to tie vines to the stake, the aim of our study was to assess the effects of microplastic particles from polypropylene (PP) and polyvinyl chloride (PVC) on the availability of macro (potassium (K), Potassium (K), calcium (Ca), magnesium (Mg) and phosphate (P)) and micronutrients (iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn)) in two vineyard soils contrasting in pH and mineralogy. For this purpose, a short-term soil incubation experiment (120 days) was carried out in which the soil samples were enriched with micro-PP and micro-PVC particles. After the incubation period, macro- and micronutrient availability were measured.

EFFECTS OF INDUCED SUNBURN DAMAGES ON WHITE WINE PROPERTIES

Climate change is a great challenge for the environment and affects the wine industry as well. Sunburn damage of sensitive grapes increase with severe heat periods. Besides significant loss of yield sunburn, modifies sensory properties of the wines and may cause climate-related off-flavours. To initiate sunburn in a controlled way, in 2021 sunburn was directly induced in the vineyard with the GrapeBurner device, exposing grapes of the varieties Riesling and Pinot Blanc with UV and IR radiation. This device was first assembled by Kai Müller of the university in Geisenheim and consists of a carriage with 6 UV/IR lamps. A 15 min irradiation was applied in early September at 60°Oe. Due to the colder season in 2021 the grapes were not harmed by previous sunburn damage.

AROMA AND SENSORY CHARACTERIZATION OF XINOMAVRO RED WINES FROM DIFFERENT GREEK PROTECTED DESIGNATIONS OF ORIGIN, EFFECT OF TERROIR CHARACTERISTICS

The quality of wines has often been associated with their geographical area of production. The aim of this work was to characterize Protected Designation of Origin (PDO) Xinomavro red wines from different geographical areas of Amyndeon and Naoussa in Northern Greece, elaborated with variables that contribute to their differentiation, such as soil characteristics, altitude, monthly average temperature and rainfall.
Xinomavro fruit parcels from different vineyards within the two PDO zones (5 PDO Naoussa and 6 PDO Amyndeon) were vinified following a standard winemaking process. A total of 25 aroma compounds were quantified using gas chromatography-mass spectrometry (GC-MS) with simultaneous full scan and selected ion monitoring for data recording, and odor activity values (OAVs) were determined.