Bacteria From Hemp Seed Oil Shown to Combat Botrytis, Offering a New Biocontrol Tool for Cannabis Growers

Researchers at McGill University examined seven bacterial strains isolated from hemp seed oil to determine whether they could suppress the pathogen, which is responsible for major economic losses in cannabis cultivation and is increasingly resistant to traditional treatments. Three strains demonstrated meaningful antifungal activity when tested against a Botrytis isolate taken from cannabis. Those strains included Bacillus mojavensis HOB3, Paenibacillus HOB6 and Bacillus subtilis HOB7. The team then analyzed each strain for biosurfactant activity using different growth media, noting that the effectiveness varied significantly depending on the medium.

Among the findings, the hydrocarbon-amended extract of B. subtilis HOB7 displayed the strongest biosurfactant signal and the most substantial antifungal effect. That same activity was absent when the strain was grown in a standard lysogeny broth, a result that suggests the antifungal properties may be linked to biosurfactant production under specific conditions.

Genome analysis further identified gene clusters responsible for producing several compounds known for their antifungal capabilities, including polymyxin B, fusaricidin B, fengycin and surfactin.

According to the researchers, this is the first documented evidence that bacteria occurring naturally in hemp seed oil may serve as biocontrol agents against fungal pathogens affecting cannabis.