Probiotic Potential of Enterococcus lactis GL3 Strain Isolated from Honeybee (Apis mellifera L.) Larvae: Insights into Its Antimicrobial Activity Against Paenibacillus larvae
by
, , , , ,
Manhong Ye
1,2,*
,
Yinhong Jiang
1,
Qiannan Han
1,
Xiaoyuan Li
1,
Chuang Meng
2,
Chao Ji
3,
Feng Ji
4 and
Bin Zhou
5,* 1
College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
2
Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
3
Fubiao Biotech Co, Ltd., Huaian 211799, China
4
Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100089, China
5
College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
*
Authors to whom correspondence should be addressed.
Vet. Sci. 2025, 12(2), 165; https://doi.org/10.3390/vetsci12020165
Submission received: 15 January 2025
/
Revised: 6 February 2025
/
Accepted: 11 February 2025
/
Published: 13 February 2025
(This article belongs to the Section Veterinary Microbiology, Parasitology and Immunology)
Simple Summary
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.
Abstract
This study aimed to address the need for effective probiotics and antibacterial agents to combat American foulbrood disease in honeybees, caused by Paenibacillus larvae. In the context of declining honeybee populations due to pathogens, we isolated eight lactic acid bacteria (LAB) strains from honeybee larvae (Apis mellifera L.) and evaluated their probiotic potential and inhibitory effects against P. larvae. Methods included probiotic property assessments, such as acid and bile salt resistance, hydrophobicity, auto-aggregation, co-aggregation with P. larvae, antioxidant capacities, osmotolerance to 50% sucrose, and antibiotic susceptibility. Results indicated that the GL3 strain exhibited superior probiotic attributes and potent inhibitory effects on P. larvae. Whole-genome sequencing revealed GL3 to be an Enterococcus lactis strain with genetic features tailored to the honeybee larval gut environment. Pangenome analysis highlighted genetic diversity among E. lactis strains, while molecular docking analysis identified aborycin, a lasso peptide produced by GL3, as a promising inhibitor of bacterial cell wall synthesis. These findings suggested that GL3 was a promising probiotic candidate and antibacterial agent for honeybee health management, warranting further investigation into its in vivo efficacy and potential applications in beekeeping practices.
