# Bioprospecting Honey-Derived Microorganisms for the Biological Control of Phytopathogens

## TL;DR

Honey-derived bacteria show strong potential as sustainable alternatives to synthetic pesticides for controlling plant pathogens.

## Contribution

Honey is proposed as a novel reservoir for stress-tolerant biocontrol agents with efficacy comparable to commercial products.

## Key findings

- Initial screening with standard organisms effectively identified strains with antimicrobial potential against phytopathogens.
- Two Bacillus velezensis strains from honey exhibited high inhibition of phytopathogens and caused hyphal deformities.
- Honey-derived strains showed efficacy comparable to commercial biocontrol agents.

## Abstract

Microbial biological control agents are a sustainable alternative to synthetic pesticides, yet their widespread application is limited by a lack of environmental resilience of commercial products. To address this, we exploited honey—a stringent ecological niche—as a reservoir for stress-tolerant bacteria. In this study, the bioprospection utilizing five types of commercially available honeys yielded a collection of 53 bacteria and 10 fungi. All bacterial isolates were evaluated for antimicrobial activity against a laboratory-standard bacterium and yeast, and six economically relevant phytopathogenic microorganisms. Initial screening with standard laboratory organisms proved to be an efficient method to detect strains with antimicrobial potential, correlating significantly with further phytopathogen inhibition (Spearman’s r = 0.4512, p = 0.0005). Two promising strains, M2.7 and M3.18, were selected for quantitative dual-culture assays along with molecular identification using 16S rDNA and gyrA gene sequencing, classifying them as Bacillus velezensis. These strains exhibited high inhibitory effects against the pathogens (p > 0.001), often with equivalent efficacy to the commercial biocontrol strain, and also induced significant phytopathogen hyphal deformities, such as increased septation and swelling. These findings support honey as a viable source of robust biocontrol agents, offering a sustainable strategy to substitute or complement current agrochemicals.