Reuterin-based broad-spectrum antifungal treatment for pre- and post-harvest crop protection

Overview

Reuterin is a naturally produced antimicrobial compound generated by the bacterium Lactobacillus reuteri. This research program is developing reuterin as a broad-spectrum antifungal agent for protecting fruits, vegetables, and cereal crops against ascomycete pathogens during both pre-harvest and post-harvest stages. The goal is to provide growers and post-harvest handlers with an effective, bio-based alternative to conventional synthetic fungicides while maintaining product quality and shelf life.

The work addresses economically significant crop diseases caused by Botrytis cinerea (gray mold), Colletotrichum acutatum (anthracnose), Rhizopus stolonifer (soft rot), and Penicillium expansum (blue mold). These pathogens cause major losses across the berry, grape, stone fruit, and vegetable supply chains. By targeting multiple pathogens with a single natural compound, the technology aims to simplify disease management programs and reduce dependence on synthetic chemistries.

Technical specifications

Key features:

• Reuterin applied at 50–100 mM achieves antifungal effects comparable to fludioxonil at 5 mM, reducing spore counts by approximately 4 logs across most tested strains
• Efficacy demonstrated against Botrytis cinerea, Colletotrichum acutatum, Rhizopus stolonifer, and Penicillium expansum on strawberries stored at 4 °C
• No negative impact on fruit quality parameters at effective concentrations, supporting consumer-acceptable end products
• Validated using a custom fractional factorial design (n=30) across two randomized blocks, with results confirmed by predictive profiler analysis and statistical significance (p < 0.05)
• Bio-based, naturally derived active compound compatible with integrated pest management and reduced-residue production strategies

How it works:

Reuterin acts directly on fungal spores and mycelium, inhibiting growth of ascomycete pathogens on the surface of treated produce. The compound is applied to inoculated and non-inoculated fruit, and efficacy is measured by spore count reduction and quality assessment at the end of storage. The custom fractional factorial design enables efficient screening of multiple concentration combinations of reuterin and fludioxonil, while the predictive profiler identifies optimal dosage ranges that balance pathogen control with fruit quality preservation.

Technology readiness level

The technology is currently at an early-to-mid stage of development, with efficacy demonstrated under controlled laboratory and small-scale storage conditions on strawberries. Initial validation has confirmed broad-spectrum antifungal activity and quality preservation at effective concentrations.

Next steps include:

• Optimizing reuterin production under varying growth conditions for Lactobacillus reuteri to improve yield and cost-effectiveness
• Extending efficacy testing to Fusarium species across a wider concentration range (0–500 mM), with planned collaboration with a Mexican partner on chickpea
• Conducting parallel validation trials on Botrytis cinerea in strawberries (Canada) and grapes (Mexico) to confirm performance across additional crops and geographies
• Scaling toward field and commercial storage trials as production optimization and broader pathogen coverage are completed, with an estimated two-year horizon to advance the program

The technology is ready for collaborative development with industry partners interested in bio-based crop protection, post-harvest treatment formulations, and sustainable agriculture solutions.