Growth of honey bee bacteria in whey-based medium

Emma Mattonai

Master's thesis

Abstract:

The Apis mellifera pollinator influences genomic diversity in plant communities and contributes to ecosystem structure. Concerns have arisen from the disappearance of bee colonies due to pollution, biocides and diseases. The use of probiotics in the bee diet can improve the gastrointestinal microbiota, promoting metabolic balance and fortifying colonies against stressors and diseases. Six beneficial strains, isolated from the gastrointestinal tract of worker bees, were identified based on the 16S rRNA gene as Lactobacillus melliventris, Lb. apis, Lb. helsingborgensis, Lb. kimbladii and Bifidobacterium asteroides. A whey-based medium was prepared by lactose hydrolysis using β-galactosidase, given the indigestibility of lactose by the beneficial strains and also by bees. Two different whey samples i.e. a fresh whey sample and a whey sample frozen for 24 hours were used. Conditions of using galactosidase were optimized, identifying the products by proton nuclear magnetic resonance (1H NMR). Considering the percentage of converted lactose, the fresh wheybased medium was selected and inoculated with the strains. The bacterial growth in the fresh whey-based medium, leading to the release of metabolites such as organic acids (acetic, lactic and succinic acid), was analyzed by the quantitative 1H NMR, at 24 and 48 hour. Whey is a suitable product for industrial growth of potential honey bee probiotic bacteria. Spectrum of organic compounds produced during the fermentation suggests a possible use as a drink suitable for human consumption. This research represents a basis for cheap large scale production of these bacteria. Abbreviations: NMR, Nuclear Magnetic Resonance; LAB, lactic acid bacteria; AMPs, antimicrobial peptides; GI, gastrointestinal; GRAS generally recognized as safe; GC, guanine and cytosine; HMOs, human milk oligosaccharides; SCFAs, short chain fatty acids; F6PPK, fructose-6-phosphate-phosphoketolase; M.R.S., de Man, Rogosa and Sharpe; TPY, Trypticase Phytone Yeast.

Keywords

c, a, b

Language used: English

Date on which the thesis was submitted / produced: 17. 2. 2024

Thesis defence

• Date of defence: 21. 2. 2024
• Supervisor: doc. Ing. Jaroslav Havlík, Ph.D.
• Reader: Chiara Sanmartin, externi

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme:
Sustainable Agriculture and Food Security