Med. Weter. 72 (7), 430-434, 2016

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Aneta A. Ptaszyńska, Grzegorz Borsuk, Wiesław Mułenko, Joanna Wilk
Impact of vertebrate probiotics on honeybee yeast microbiota and on the course of nosemosis
The natural intestine microbiota of honeybees is dominated by Gram-negative bacteria from such families as: Enterobacteriaceae, Alcaligenaceae and Pseudomonadaceae, less numerous are Gram-positive bacteria, yeasts and other fungi. Our research was focused on the impact of commercial vertebrae probiotics, on honeybees’ intestine yeast number, hemolymph lysozyme activity and nosemosis development. The diet of honeybees was supplemented with two vertebrate probiotics recommended in beekeeping management. The former consisted of Lactobacillus casei, L. plantarum, Saccharomyces cerevisiae, and Rhodopseudomonas palustris. The latter consisted of L. acidophilus, L. delbrueckii, and Bifidobacterium bifidum. Yeasts isolated from honeybees’ intestine and detected in our research belonged to two genera: Candida and Saccharomyces. The average number of yeast Colony Forming Units (CFUs) in uninfected honeybees fed only sugar syrup was 3850 (±400.33) and after Nosema spp. infection the number rose to 19500 (±1644.40) per one honeybee. The addition of a probiotic decreased the number of detected yeast CFUs in both groups of infected and uninfected honeybees. Nosema infection did not affect lysozyme activity; therefore it was the administration of probiotics that had the main impact on the rise of lysozyme level. Most likely very vivid probiotic bacteria were treated as invaders by honeybees’ immune defense, which resulted in almost 40% rise observed in lysozyme activity. Furthermore, probiotic supplementation accelerated the nosemosis development even twofold. Probably, increased acidity of the honeybees’ intestine, which is a consequence of the uncontrolled growth of lactic acid bacteria, created conditions favorable to faster nosemosis development. Therefore, every administration of diet supplements with live microorganisms whose impact on honeybees biology and physiology is not well studied should be carried out with the greatest caution.
Key words: Apis mellifera, nosemosis, yeast, Candida, Saccharomyces, diet supplements, lysosyme activity