Antimicrobial Activity of Essential Oils Against the Fungal Pathogens Ascosphaera apis and Pseudogymnoascus destructans
Fungal pathogens are a growing worldwide concern. Declines in a number of economically and agriculturally important plant and animal species pose a significant threat to both biodiversity and food security. Although many effective antifungal agents have been identified, their toxicity often precludes their use with food products or sensitive animal species. This has prompted the exploration of natural products as effective treatment compounds. In the present study, several essential oils were tested for their capacity to limit the growth of the fungal pathogens Ascosphaera apis and Pseudogymnoascus destructans, the causative agents of chalkbrood disease among honey bee larvae and white-nose syndrome among bats, respectively. Essential oils of cinnamon bark, citronella, lemongrass, and orange were exposed to A. apis in contact-dependent oil-agar suspensions as well as in contact-independent shared airspaces. Essential oils of cinnamon bark, citronella, and lemongrass were exposed to P. destructans in contact-dependent oil-agar suspensions. All compounds were found to significantly inhibit mycelial growth at low concentrations, suggesting the potential for these natural products to be used for controlling these and other select fungal pathogens.
KeywordsAscosphaera apis Pseudogymnoascus destructans Fungal pathogens Antifungal Inhibition Essential oils Cinnamon bark Citronella Lemongrass Orange Volatile organic compounds
The authors would like to thank Kevin Keel for providing the P. destructans fungal cultures used in this study. The authors would also like to thank Ariel J. Santiago for his support with statistical analyses.
LK performed the research, KTG prepared the manuscript, and SAC, Jr. and CTC conceived and designed the study. LK and KTG analyzed the data.
This study was funded by the Georgia State University Department of Biology.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
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