Antimicrobial effects of cannabidiol on select agriculturally important Clostridia

Authors: LAKES, JOURDAN - Oak Ridge Institute For Science And Education (ORISE); Ferrell, Jessica; Berhow, Mark; Flythe, Michael

Submitted to: Anaerobe
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2024
Publication Date: 3/25/2024
Citation: Lakes, J.E., Ferrell, J.L., Berhow, M.A., Flythe, M.D. 2024. Antimicrobial effects of cannabidiol on select agriculturally important Clostridia. Anaerobe. 87. Article 102843. https://doi.org/10.1016/j.anaerobe.2024.102843.
DOI: https://doi.org/10.1016/j.anaerobe.2024.102843

Interpretive Summary: Clostridia are a class of bacteria that live in a variety of environments including humans, animals, soil, and plant tissues. These bacteria can be helpful, neutral, or harmful in these environments. Certain Clostridia have undesirable effects on agricultural systems including animal health and performance, and forage preservation (i.e., silage). In animals, some Clostridia breakdown proteins in the diet and produce ammonia, which is removed from the animal in the urine. This process reduces weight gain in cattle because there is less protein available. In silage, some Clostridia prevent the proper preservation of plant material (forage) and result in spoiled forage. In some cases, antibiotics or supplements lessen negative effects of Clostridia, but it is important to identify alternatives so that antibiotics can be saved for medical situations. In this study, we investigated the antimicrobial capabilities of cannabidiol (CBD) from hemp against five agriculturally relevant members of the Clostridia. When these five bacteria were exposed to CBD at varying concentrations, we found that the growth of all five were inhibited. We also found that CBD significantly reduced the amount of ammonia produced by all five bacteria. These results show that hemp compounds could be used to control undesirable bacteria in different agricultural systems.

Technical Abstract: Class Clostridia are ubiquitous organisms occupying several niches across multiple environments and can be either commensal or antagonistic in these associations. Amino acid-fermenting Clostridia have undesirable effects on agricultural systems such as proteolysis in silage, ammonia production in the rumen, and animal disease. In some cases, antibiotics mitigate detrimental effects of Clostridia, but antibiotic resistance makes it imperative to find alternatives, such as inhibitory compounds produced by plants. In this study, the inhibitory capabilities of cannabidiol were tested against five agriculturally relevant, amino acid fermenting members of class Clostridia: Clostridium sporogenes (MD1), Peptostreptococcus spp. (BG1), Clostridioides difficile (9689), Acetoanaerobium sticklandii (SR), and Clostridium aminophilum (F). When growth media were amended with 10-fold dilutions of decarboxylated cannabidiol from 8.6 mg mL-1 – 0.86 µg mL-1, the growth of each species was inhibited to varying degrees between 8.6 mg mL-1 and 8.6 µg mL-1. Ammonia production by all Clostridia was measured in the presence or absence of cannabidiol at 8.6 µg mL-1 (SR, MD1, and 9689) and 86 µg mL-1 (F and BG1). Cannabidiol was found to reduce the ammonia produced by all species.