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  • Author: Zbigniew Lipiński x
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Marek Farjan, Krystyna Żółtowska, Zbigniew Lipiński, Elżbieta Łopieńska-Biernat and Małgorzata Dmitryjuk

Abstract

The colony collapse disorder is a growing problem world-wide. For this reason, we were prompted to search for natural and harmless agents that could improve the living conditions of honey bees. This group of agents includes exogenous antioxidants, such as ascorbic acid, which boost natural immunity. We analysed the effect of vitamin C supplementation on carbohydrate metabolism in the developing honey bee worker brood. The total carbohydrate content and the concentrations of glycogen, trehalose, maltotriose, fructose, and glucose were estimated. The correlations between sugar content and the activity of the main hydrolases of carbohydrate metabolism - α-amylase, glucoamylase, trehalase, maltase, and sucrase - were determined. The addition of vitamin C to the diet of wintering bees did not impair their sugar metabolism. Vitamin C supplements exerted a positive effect by significantly increasing glycogen and trehalose concentrations in the initial phase of development and in newly emerged workers. Vitamin C did not induce significant changes in the developmental profile of carbohydrate degrading enzymes, except for the earliest stage of larval development when enzyme activity levels were below those noted in the control group.

Open access

Elżbieta Łopieńska–Biernat, Małgorzata Dmitryjuk, Ewa Zaobidna, Zbigniew Lipiński and Krystyna Żółtowska

Abstract

The aim of the present research was to determine the basic composition of the organic compounds present in extracts from Varroa destructor, a parasitic mite of the honeybee. The total protein content was 9.16 ± 0.82 mg/100 mg of body weight, lipid content was 9.81 ± 1.99 mg/100 mg, and carbohydrate content was 26.67 ± 4.52 mg/100 mg. The triacylglycerol content was 2.40 ± 0.86 mg/100 mg and the cholesterol content was 0.14 ± 0.02 mg/100 mg. Thin layer chromatography indicated that phospholipids comprised the major part of the lipid component; cephalins (78%), cerebrosides (16%), and lecithins (6%) were identified in the phospholipid pool. Glucose (23.6 ± 4.52 mg/100 mg) was the main carbohydrate, followed by glycogen (5.43 ± 1.23 mg/100 mg) and trehalose (0.35 ± 0.07 mg/100 mg). Enzyme-linked immunosorbent assays detected two major glycogen metabolism enzymes, glycogen phosphorylase and glycogen synthase. Among the enzymes metabolising disaccharides, maltase (24.7 ± 2.38 μmol/mg protein) and trehalase (14.81 ± 5.21 μmol/mg protein) presented the highest activity. Saccharose and lactose were hydrolysed to a minor extent. These are the first measurements of the basic composition of the mite body. Although these data are not exhaustive, they may serve as the basis for further research on the metabolism of V. destructor, particularly concerning lipid metabolism.

Open access

Joanna Wojtacka, Beata Wysok, Zbigniew Lipiński, Małgorzata Gomółka-Pawlicka, Helena Rybak-Chmielewska and Agnieszka Wiszniewska-Łaszczych

Abstract

A total of 102 honey samples collected from small apiaries (≤ 20 hives) in Poland were analysed for the presence of Clostridium botulinum spores. The samples were prepared using the dilution centrifugation method and cultured in parallel in cooked meat medium (CMM) and tripticase peptone glucose yeast (TPGY) enrichment broths. Identification of toxin types A, B, and E of Clostridium botulinum strains was performed with the use of the multiplex PCR method. Positive samples were also subjected to quantitative analysis with the use of Clostridium botulinum Isolation Agar Base (CBAB). The prevalence analysis showed 22 (21.6%) samples contaminated with C. botulinum spores. The major serotype detected was botulin neurotoxin type A – 16 (72.7%) whereas type B was found in 3 (13.6%) honey samples and type E also only in 3 (13.6%) honey samples. Dual-toxin-producing strains were noted. The average quantity of spores in PCR - C. botulinum positive samples was 190 in 1 gram of honey.