Probiotic Potential of Enterococcus lactis GL3 Strain Isolated from Honeybee (Apis mellifera L.) Larvae: Insights into Its Antimicrobial Activity Against Paenibacillus larvae

Abstract

Honeybees are crucial for pollination, but their populations are declining due to diseases like American foulbrood, caused by the bacterium Paenibacillus larvae. This disease is lethal to honeybee larvae and can lead to colony collapse. To combat this, scientists are looking for probiotics, or beneficial bacteria, that can help honeybees fight off pathogens. In this study, researchers isolated eight strains of lactic acid bacteria from honeybee larvae and tested their probiotic properties and inhibitory effects against the growth of P. larvae. One strain, called GL3, stood out because it showed strong resistance to acid and bile salts, had good antioxidant properties, and could effectively inhibit the growth of P. larvae. Further analysis revealed that GL3 belonged to the species Enterococcus lactis and had genetic features that helped it survive and thrive in the honeybee larval gut. Additionally, GL3 could produce a compound called aborycin that had the potential to disrupt the cell wall of P. larvae, making it a promising antibacterial agent. These findings suggested that GL3 could be a valuable probiotic for honeybee health and may help reduce the impact of American foulbrood disease, benefiting honeybee populations and the ecosystems they support.