terclim by ICS banner
IVES 9 IVES Conference Series 9 PHENOTYPIC DIVERSITY AND BIO-PROTECTION CAPABILITY OF METSCHNIKOWIA SP. IN OENOLOGY

PHENOTYPIC DIVERSITY AND BIO-PROTECTION CAPABILITY OF METSCHNIKOWIA SP. IN OENOLOGY

Abstract

Nowadays, the trend is to reduce the use of chemical inputs in the food sector, including in oenology. One of the inputs widely used in the wine making process are sulfites, for its several properties: antimicrobial and antioxidiant. This use isn’t without consequences on consumer’s health and environment, it can lead for example to allergic reactions and pollution. To limit the addition of chemical inputs, microbial alternatives are used. It consists to inoculate in grape must, a micro-organism able to inhibit the growth of the negative indigenous flora during the phase before the fermentation and to guarantee the sensory qualities of wines. One of the specie the most used for its bio-protection capacity is the genus Metschnikowia. This project aims to study the phenotypical diversity in wine fermentative conditions and the diversity of bio-protector character of Metschnikowia sp.

To study the phenotypical diversity, 16 species of Metschnikowia within 50 strains have been selected depending their localization, their origins, and the species. These strains are used to ferment grape synthetical must, and the products of carbon central metabolism are analyzed by HPLC and the production of volatile molecules by GC-MS. In parallel, these strains are put in co-culture, with an acetic bacterium (Gluconobacter oxydans), known to lead to acetic souring, in commercial grape juice to study the interaction between yeast at 106cell/mL, and bacteria at 103cell/mL. Their growth is followed at day 0, 1, 2 and 7 through drop test on selective medium.

Similar to the fermentation aspects, the volatile profiles of the different strains were quite different, which corroborated the diversity of the Metschnikowia yeasts. The results of the drop test show an effect of bio-protection from the species Metschnikowia on the growth of G. oxydans. This work can underline both the potential of Metschnikowia yeast strains for inhibiting spoilage wine microorganisms and increasing aroma compounds.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Angèle Thiriet², Pascale Fernandez-Valle¹, Cécile Grondin², Jean-Luc Legras1,2, Carole Camarasa¹, Audrey Bloem¹

1. UMR SPO, Univ Montpellier, INRAE, Institut Agro, 34060 Montpellier, France
2. CIRM Levures, UMR SPO, Montpellier, France

Contact the author*

Keywords

wine fermentation, bioprotection, Metschnikowia, diversity

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

TANNINS AND ANTHOCYANINS KINETICS OF EXTRACTION FROM ARINARNOA, MARSELAN AND TANNAT UNDER DIFFERENT WINEMAKING TECHNIQUES

Marselan wines have an unusual high proportion of seed derived tannins from grapes having high proportions of skins, which are rich in tannins. But the causes behind this characteristic have not yet been identified. In vintage 2023 wines were made at experimental scale (9 kg by experimental unit) from Arinarnoa, Marselan and Tannat Vitis vinifera grape cultivars by traditional maceration, and by techniques aimed to increase the wine content in skin derived tannin: addition of extraction enzymes, addition at vatting of grape-skin enological tannins, or by extended maceration, known to increase the seed derived tannin contents of wines.

RED WINE AGING THROUGH 1H-NMR METABOLOMICS

Premium red wines are often aged in oak barrel. This widespread winemaking process is used, among others, to provide roundness and complexity to the wine. The study of wine evolution during barrel aging is crucial to better ensure control of wine quality.
¹H-NMR has already been proved to be an efficient tool to monitor winemaking process [1]. Indeed, it is a non-destructive technique, it requires a small amount of sample and a short time of analysis, yet it provides clues about several chemical families.

INFLUENCE OF THE THICKNESS OF OAK ALTERNATIVES ON THE COMPOSITION AND QUALITY OF RED WINES

Aging red wines in oak barrels is an expensive and laborious process that can only be applied to wines with a certain added value. For this reason, the use of oak alternatives coupled with micro-oxygenation has progressively increased over recent years, because it can reproduce the processes taking place in the barrels more economically and quickly [1]. Several studies have explored how oak alternatives [2-5] can contribute to wine composition and quality but little is known about the influence of their thickness.

EVALUATION OF THE OENOLOGICAL POTENTIAL OF NEW RESISTANT VARIETIES MEETING TYPICAL BORDEAUX CHARACTERISTICS

Varietal innovation is a major lever for meeting the challenges of the agro-ecological transition of vi-neyards and their adaptation to climate change. To date, selection work has already begun in the Bordeaux region through the Newvine project. The aim of this project is to create new vine varieties with resistance to mildew and powdery mildew, adapted to the climatic conditions of the Bordeaux region and enabling the production of wines that are in line with consumer tastes and the expected typicity of Bordeaux wines.

IMPACT OF RHIZOPUS AND BOTRYTIS ON WINE FOAMING PROPERTIES

A lot of work has been done on the impact of Botrytis on the foam of sparkling wines. This work often concerns wines produced in cool regions, where Botrytis is the dominant fungal pathogen. However, in southern countries such as Spain, in particularly hot years such as 2022, the majority fungal pathogen is sometimes Rhizopus. Like Botrytis, Rhizopus is a fungus that produces an aspartic protease.