Differential Proteomics in Dequeened Honeybee Colonies Reveals Lower Viral Load in Hemolymph of Fertile Worker Bees

The eusocial societies of honeybees, where the queen is the only fertile female among tens of thousands sterile worker bees, have intrigued scientists for centuries. The proximate factors, which cause the inhibition of worker bee ovaries, remain largely unknown; as are the factors which cause the activation of worker ovaries upon the loss of queen and brood in the colony. In an attempt to reveal key players in the regulatory network, we made a proteomic comparison of hemolymph profiles of workers with completely activated ovaries vs. rudimentary ovaries. An unexpected finding of this study is the correlation between age matched worker sterility and the enrichment of Picorna-like virus proteins. Fertile workers, on the other hand, show the upregulation of potential components of the immune system. It remains to be investigated whether viral infections contribute to worker sterility directly or are the result of a weaker immune system of sterile workers

Extending the honey bee venome with the antimicrobial peptide apidaecin and a protein resembling wasp antigen 5

Honey bee venom is a complex mixture of toxic proteins and peptides. In the present study we tried to extend our knowledge of the venom composition using two different approaches. First, worker venom was analysed by liquid chromatography-mass spectrometry and this revealed the antimicrobial peptide apidaecin for the first time in such samples. Its expression in the venom gland was confirmed by reverse transcription PCR and by a peptidomic analysis of the venom apparatus tissue. Second, genome mining revealed a list of proteins with resemblance to known insect allergens or venom toxins, one of which showed homology to proteins of the antigen 5 (Ag5)/Sol i 3 cluster. It was demonstrated that the honey bee Ag5-like gene is expressed by venom gland tissue of winter bees but not of summer bees. Besides this seasonal variation, it shows an interesting spatial expression pattern with additional production in the hypopharyngeal glands, the brains and the midgut. Finally, our immunoblot study revealed that both synthetic apidaecin and the Ag5-like recombinant from bacteria evoke no humoral activity in beekeepers. Also, no IgG4-based cross-reactivity was detected between the honey bee Ag5-like protein and its yellow jacket paralogue Ves v 5

Influence of refining of vegetable oils on minor components

Refining of crude vegetable oils involving degumming, bleaching and deodorisation has a high influence on the content of functional minor components. In this study the difference of chemical versus physical refining will be studied. Especially the reduction of the tocopherolcontent in refined oil is mainly due to oxidation of the tocopherol. Also the content of sterolsin free and esterified form is changing during the various procedures during refining. Analternative two-step deodorisation is described

Influence of refining of vegetable oils on minor components

Refining of crude vegetable oils involving degumming, bleaching and deodorization has a high influence on the content of functional minor components. In this study, the difference of chemical versus physical refining will be studied. Especially the reduction of the tocopherol content in refined oil is mainly due to oxidation of the tocopherol. Also the content of sterols in free and esterified form is changing during the various refining procedures. An alternative two-step deodorization is described

Influence of refining of vegetable oils on minor components

The traditional quality characteristics for refined vegetable oils focus on a bland taste, a light colour and a good oxidative stability. Currently, an increased interest is observed for functional minor components naturally present in oils and fats performing a beneficial nutritional effect. Refining of crude vegetable oils involving degumming, bleaching and deodorisation has a high influence on the content of functional minor components. In this study the difference of chemical versus physical refining will be studied. Especially the reduction of the tocopherol content in refined oil is mainly due to oxidation of the tocopherol. Also the content of sterols in free and esterified form is changing during the various stages of refining. As the economic value of physical deodoriser distillates is much lower compared to chemical distillates an improved deodorization technology to increase the quality of physical deodoriser distillates by condensation of the distillate in two separate fractions was developed. Free fatty acids distillated in the initial stages of the deodorization process are collected in a first distillate, followed by a condensation of tocopherols and phytosterols in a second distillate with a high economic value. The fractionated distillation of free fatty acids and tocopherols / phytosterols was achieved by optimisation of the deodorization temperature profile