Land Use Influences the Composition and Antimicrobial Effects of Propolis

Authors

Amara J. Orth, Creighton University
Emma H. Curran, Creighton University
Eric J. Haas, Creighton University
Andrew C. Kraemer, Creighton University
Audrey M. Anderson, University of Nebraska-Lincoln
Nicholas J. Mason, Creighton University
Carol A. Fassbinder-Orth, Creighton University

Document Type

Article

Date of this Version

2-28-2022

Citation

Orth, A.J.; Curran, E.H.; Haas, E.J.; Kraemer, A.C.; Anderson, A.M.; Mason, N.J.; Fassbinder-Orth, C.A. Land Use Influences the Composition and Antimicrobial Effects of Propolis. Insects 2022, 13, 239. https:// doi.org/10.3390/insects13030239

Comments

Open access.

Abstract

Honey bee propolis is a complex, resinous mixture created by bees using plant sources such as leaves, flowers, and bud exudates. This study characterized how cropland surrounding apiaries affects the chemical composition and antimicrobial effects of propolis. The chemical composition and compound abundance of the propolis samples were analyzed using Gas Chromatography- Mass Spectrometry (GC-MS) and the antimicrobial effects were analyzed using the 50% minimum inhibitory concentration (MIC₅₀) assay against four relevant bee pathogens, Serratia marcescens, Paenibacillus larvae, Lysinibacillus sphaericus, and Klebsiella pneumoniae. Propolis composition varied significantly with apiary, and cropland coverage predicted mean sum abundance of compounds. The apiary with the highest cropland coverage exhibited significantly higher MIC₅₀ values for S. marcescens and K. pneumoniae compared to other apiaries. These results demonstrate that agricultural land use surrounding honey bee apiaries decreases the chemical quality and antimicrobial effects of propolis, which may have implications for the impacts of land use on hive immunity to potential pathogens.