IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Exogeneous C-S lyase enzyme, a potential tool for thiol enhancement in wine or beer?

Exogeneous C-S lyase enzyme, a potential tool for thiol enhancement in wine or beer?

Abstract

Varietal thiols are considered for years as key aroma compounds in many wines. Their main origin is the cleavage during alcoholic fermentation of S-conjugate precursors present in grapes and musts, even if the levels of precursors already identified struggle to completely explain the levels of thiols found in wine.
In this bioconversion process, yeast is the key since the cleavage of thiol precursors has been demonstrated to be due to the internal C-S lyase activity of the yeast strains. Whatever the intrinsic capacity of the yeast and the regulation mechanisms identified for the transportation of thiol precursor into the cell, the conversion yield remains very low, estimated in most cases at 1%. In this context, the use of exogenous C-S lyases could be an alternative option to reveal a larger part of the thiol aroma.
Our study focused on the characterization of a recombinant C-S lyase model obtained by from Lactobaccilus delbrueckii subsp. bulgaricus, expressed in E. coli [1] to investigate the possibility of using such enzymes in different matrices such as wine, beer or directly hops, known to be rich in thiol precursors.
A spectrophotometric method was developed for the quantification of the C-S lyase activity, using commercially available S-4-nitrophenyl-L-cysteine (Cys(4NP)). This method was then used to study the specificity of substrate and potential competitor recognition, still using Cys(4NP) but also G-4NP, Cys(4NP)-Gly and γGlu-Cys(4NP) conjugates, which were specifically synthesized in our lab, based on our previous results [2].
The C-S lyase we used was able to cleave efficiently Cys(4NP), but not glutathione and dipeptide 4NP-S-conjugates. As expected, pH emerged as a key parameter: no reaction at wine pH (2.8-3.5), low activity at beer pH (4.5-5.6) and > 80% of activity at pH above 6. Assays with N-Ac-Cys(4NP) confirmed that a free amine group on the substrate was compulsory for recognition by the enzyme and subsequent cleavage of the substrate. Free cysteine has also been demonstrated to compete with Cys(4NP) resulting in a dramatic decrease in conversion efficiency.
These first results documented the possibility of using such enzyme in the different matrices, highlighting the constraints for the subsequent identification of C-S lyase more suitable to wine or beer productions

References

[1] Allegrini, A.; Astegno, A.; La Verde, V.; Dominici, P. Characterization of C-S lyase from Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 and its potential role in food flavor applications. J. Biochem. 2017, 61, 349−360.
[2] Bonnaffoux, H., Roland, A., Rémond, E., Delpech, S., Schneider, R., & Cavelier, F. (2017). First identification and quantification of S-3-(hexan-1-ol)-γ-glutamyl-cysteine in grape must as a potential thiol precursor, using UPLC-MS/MS analysis and stable isotope dilution assay. Food Chemistry, 237, 877–886.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Clerat Luigi1, Vives Eric1, Cavelier Florine2, Remond Emmanuelle2 and Schneider Rémi3

1PhyMedExp – Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046]
2Institut des biomolécules Max Mousseron (IBMM) – UMR-5247 – CNRS
3Oenobrands Montpellier FR

Contact the author

Keywords

C-S lyase, varietal thiol precursors, wine aroma, S-conjugates

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Sustaining wine identity through intra-varietal diversification

With contemporary climate change, cultivated Vitis vinifera L. is at risk as climate is a critical component in defining ecologically fitted plant materiel. While winegrowers can draw on the rich diversity among grapevine varieties to limit expected impacts (Morales-Castilla et al., 2020), replacing a signature variety that has created a sense of local distinctiveness may lead to several challenges. In order to sustain wine identity in uncertain climate outcomes, the study of intra-varietal diversity is important to reflect the adaptive and evolutionary potential of current cultivated varieties. The aim of this ongoing study is to understand to what extent can intra-varietal diversity be a climate change adaptation solution. With a focus on early (Sauvignon blanc, Riesling, Grolleau, Pinot noir) to moderate late (Chenin, Petit Verdot, Cabernet franc) ripening varieties, data was collected for flowering and veraison for the various studied accessions (from conservatory plots) and clones. For these phenological growing stages, heat requirements were established using nearby weather stations (adapted from the GFV model, Parker et al., 2013) and model performances were verified. Climate change projections were then integrated to predict the future behaviour of the intra-varietal diversity. Study findings highlight the strong phenotypic diversity of studied varieties and the importance of diversification to enhance climate change resilience. While model performances may require improvements, this study is the first step towards quantifying heat requirements of different clones and how they can provide adaptation solutions for winegrowers to sustain local wine identity in a global changing climate. As genetic diversity is an ongoing process through point mutations and epigenetic adaptations, perspective work is to explore clonal data from a wide variety of geographic locations.
Read More

Mining microbiome data to identify antagonists of grapevine downy mildew (Plasmopara viticola)

Vineyards are home to a myriad of microorganisms that interact with each other and with the vines. Some microorganisms are plant pathogens, such as the oomycete Plasmopara viticola, causing grapevine downy mildew. Others have a positive effect on vine health, such as disease biocontrol agents. These beneficial plant-microbe and microbe-microbe interactions have gained more attention in recent years because they could represent an alternative to the use of fungicides in viticulture.

Read More

Enological, economical, social and viticulture ”terroir” units as fundamental elements of mosaic of “big” zoning

Nous savons tous très bien qu’on a assisté au cours de ces dix dernières années à une éclosion soudaine de recherches sur le zonage viti-vinicole qui, à partir par exemple du modèle du concept de “terroir”, se sont de plus en plus enrichies en passant aux “Unités ou Systèmes de Transformation” (UTTE) et “Valorisation” (UTCE) pour terminer avec les “Systèmes productifs globaux du Territoire” (UTB) comprenant en filière les aspects existentiels (UTBES), sociaux (UTBSO) et économiques (UTBEC) hypothisés dans le “GRANDE ZONAZIONE: Grand zonage” (MORLAT R., 1996, CARBONNEAU A., 1996, TOUZARD J.M. 1998, CARBONNEAU A., CARGNELLO G., 1996, 1998, CARGNELLO G., 1994, 1995, 1996, 1998, 1999, 2001, -MILOTIC A., CARGNELLO G., PERSURIC G., 1999, PERSURIC G., STAYER M., CARGNELLO G., 2000, MILOTIC A., OPLANIC M., CARGNELLO G., PERSURIC G., 2000).

Read More

Accumulation of deleterious mutations in grapevine and its relationship with traits of interest for wine production and resilience

Deleterious mutations that severely reduce population fitness are rapidly removed from the gene pool by purifying selection. However, evolutionary drivers such as genetic drift brought about by demographic bottlenecks may comprise its efficacy by allowing deleterious mutations to accumulate, thereby limiting the adaptive potential of populations. Moreover, positive selection can hitchhike mildly deleterious mutations due to linkage caused by lack of recombination. Similarly, in the context of species domestication, artificial selection mimics these evolutionary processes, which can have undesirable consequences for production and resilience. In this study, we evaluated the extent of the accumulation of deleterious mutations and the magnitude of their effects (also known as genetic load) at the whole-genome scale for ca.

Read More

Evaluating the suitability of hyper- and multispectral imaging to detect endogenic diseases in grapevine

Endogenic diseases often arise from pathogens that exist within the plant tissue, including fungi, bacteria, and viruses, which can remain latent and then emerge under stress conditions or favorable environmental conditions, causing symptoms that weaken vines or can lead to plant death.

Read More