Metschnikowia pulcherrima as a biocontrol tool for grapevine protection

Abstract

Bioprotection is emerging as an innovative technique for preserving grape health contrary to traditional approaches based on the addition of external chemical agents (1). The presence of fungicide residues in grapes and musts may interfere in alcoholic fermentation kinetics, leading to fermentation delays and negative sensory impacts on the final wine (2). Metschnikowia pulcherrima is a non-Saccharomyces yeast that has demonstrated remarkable antagonistic capacity against various phytopathogenic fungi, mainly associated with its high affinity for iron (3,4). This property makes M. pulcherrima an ideal candidate for preventive applications in vineyards, thus constituting a sustainable agricultural strategy by supporting natural biocontrol and reducing reliance on chemical inputs. The aim of this study was to explore a bioprotective strategy through the application of M. pulcherrima in grapevine. A native strain exhibiting the highest antimicrobial activity was first selected following established procedures (5). Subsequently, a field trial was conducted in a white-grape vineyard using a randomized complete block design comprising three vine rows. Within each row, three blocks of 30 vines were assigned to one of the following treatments, applied by spraying two weeks before harvest: 800 mL of water (WT), a commercial yeast suspension containing 2–3 × 10⁷ CFU/mL (CY), or the selected M. pulcherrima strain at the same concentration (208T). For microbiological analyses, 100 berries were aseptically collected from each treatment 30 minutes after spraying (time 0) and again at harvest (after 2 weeks). Quantification of molds, yeasts, lactic and acetic acid bacteria was performed on selective media following OIV recommendations (6) and implantation of both strains was confirmed at the two sampling times by PCR-RAPD. Finally, each vine block was vinified independently to assess the impact of this in-field application on the final wine quality. Results obtained showed that 208T treatments resulted in a higher reduction in Aspergillus niger counts (72%) compared to control plots, together with a complete inhibition of Gluconobacter spp. Although CY treatments also reduced both microorganisms, this effect was less pronounced (6% and 54%, respectively), indicating a higher bioprotective capacity of 208T. RAPD-PCR analysis confirmed the correct implantation of each strain in their corresponding blocks, being both strains quantified at 10³–10⁴ CFU/mL after racking.

References

1. Gianvito PD, Englezos V, Rantsiou K, Cocolin L. Bioprotection strategies in winemaking. Int J Food Microbiol. 2 de marzo de 2022; 364:109532.

2. Gava A, Emer CD, Ficagna E, Fernandes de Andrade S, Fuentefria AM. Occurrence and impact of fungicides residues on fermentation during wine production– A review. Food Addit Contam Part A. 3 de junio de 2021; 38(6):943-61.

3. Liu Y, Yan H, Yao J, Yan Y, Zhou J, Shi W. Bioprospection of Metschnikowia pulcherrima as biocontrol agents against gray mold on grapes with their potential modes of action. Int J Food Microbiol. 2 de noviembre de 2025; 442:111383.

4. Lombardo MF, Panebianco S, Restuccia C, Cirvilleri G. Biocontrol Efficacy of Metschnikowia spp. Yeasts in Organic Vineyards against Major Airborne Diseases of Table Grapes in the Field and in Postharvest. Foods. 21 de septiembre de 2023; 12(18):3508.

5. Kanjan P, Sakpetch P. Effect of antifungal compounds secreted by Lactiplantibacillus plantarum 124 against Aspergillus flavus and Penicillium sp. and its application in Kaeng-Tai-Pla-Haeng to extend the shelf life. Int J Food Sci Technol. 2023; 58(10):5376-87.

6. International Organisation of Vine and Wine (OIV). (2021). Resolution OIV OENO 632 2021: Analytical and microbiological control techniques – Analyses common to all monographs. OIV.