Functionality of honeybee (Apis mellifera) fructophilic microbiota

Author: Irakli Janashia
Keywords: Apis mellifera, Microbiota
Annotation:

honeybee symbiont Lactic Acid Bacteria (LAB) are supposed to play key role in colony functioning: acting as an immune enhancers, restricting pathogen invasion, aiding nutrient uptake and participating in beebread transformation. Pollen is protein rich food of honeybees. The lactic fermentations were suggested to be protective factors beebread against deletorious microbial spoilages. Insufficient data has been provided in scientific literature on the microbial ecosystem of the beebread. Presented study aimed: to describe a role of Apis mellifera colony microbial dwellers by identification of the functions of indigenous LAB in bee life cycle. Five samples of beebread were taken from one healthy honeybee colony, different fungal strains were isolated, identified and used in experiments, where pollen fermentation was carried out in laboratory conditions using beebread LAB isolates. SDS PAGE, Starch Agar Plate & Well Diffusion methods were used to determine proteolytic, amylolytic, antibacterial and antifungal activities of those microroganisms as key features predetermining their symbiotic nature. In total, 15 fungal strains were identified. Only 3 among all isolates: Candida sp., Zygosaccharomyces rouxii and one fungus Aspergillus niger were able to replicate on the pollen substrate. Growth of those fungal strains was inhibited in presence of LAB strains: Lactobacillus kunkeei, Fructobacillus tropaeoli and Fructobacillus fructosus. No proteolytic, amylolytic or antibacterial activities was detected. Indigenous LAB strains display niche specific character taking part in beebread formation as effective fermentators and limiting the growth of fungal flora, thus protecting it from the spoilage. Furthermore, fungus Aspergillus niger against which the above-cited LAB strains are active, is causative agent of honeybee larvae disease – stonebrood, which causes considerable damage in industrial beekeeping.