Postharvest Yeast Treatments Control Strawberry Rots and Shift the Fruit Microbiome, Study Finds

Why It Matters

The results provide growers with an eco‑friendly tool that reduces reliance on synthetic fungicides and leverages the fruit microbiome to extend shelf life, addressing both food‑waste and regulatory pressures.

Key Takeaways

• Aureobasidium pullulans and Metschnikowia pulcherrima cut gray‑mold by ~50%.
• Yeast treatments matched efficacy of commercial M. fructicola bio‑fungicide.
• Fruit firmness, sweetness, and acidity remained unchanged after yeast application.
• Metabarcoding showed reduced Botrytis and increased beneficial Achromobacter taxa.
• Yeast colonization reshaped both fungal and bacterial communities on strawberries.

Pulse Analysis

Post‑harvest loss accounts for up to 30% of strawberry production, prompting the industry to seek alternatives to conventional fungicides that can leave residues and face tightening regulations. Biological control agents, particularly antagonistic yeasts, have emerged as a promising class because they are generally recognized as safe, inexpensive to produce, and can be applied during existing packing line operations. By targeting the early stages of infection, these microbes can intervene before spoilage becomes visible, offering a proactive approach to quality preservation.

In the recent peer‑reviewed trial, researchers screened dozens of epiphytic and endophytic yeasts and identified Aureobasidium pullulans and Metschnikowia pulcherrima as the most potent against naturally occurring Botrytis infections. Applied at commercial‑scale concentrations, the yeasts reduced gray‑mold incidence by roughly half after ten days of refrigeration and two days of retail display, a performance on par with a market‑available Metarhizium‑based bio‑fungicide. Importantly, standard quality metrics—firmness, total soluble solids, and titratable acidity—were statistically indistinguishable from untreated fruit, confirming that the biocontrol does not compromise consumer‑perceived freshness.

Beyond direct pathogen suppression, metabarcoding data revealed a reshaped microbiome: the introduced yeasts colonized the fruit surface, displaced Botrytis, and fostered beneficial bacterial genera like Achromobacter. This microbiome engineering effect could create a protective ecological niche that deters future infections, a concept gaining traction in post‑harvest science. For growers, the dual benefit of disease control and microbiome modulation may translate into lower input costs, reduced pesticide residues, and longer market windows, positioning yeast‑based treatments as a strategic asset in sustainable supply chains.