Team:Wageningen UR/overview
Honeybees are incredibly important pollinators, responsible for the abundance and diversity of our food. Unfortunately, honeybees are in trouble: Varroa destructor, a mite with a fitting name, weakens the bees and spreads diseases. iGEM Wageningen UR 2016 aims to save the bees from V. destructor through the use of a very specific toxin that does not harm bees or humans. Honeybees pollinate an enormous range of crops, which and they do so very quickly. This makes them very important for pollination of monocultures, where we get the majority of our food from. Because some crops like apples and almonds rely heavily on bee pollination, the diversity of our diet depends on the well-being of these insects. Therefore, it is of key importance to keep bees alive and healthy. Unfortunately bees are not doing well at all. There has been a sustained loss of bee colonies in the western world for at least 10 years. Last year, US beekeepers lost over 40% of their colonies!Such numbers are unacceptable, especially when we consider the enormous relevance of bees for our food supply. What causes the loss of bee colonies? According to the beekeepers we have spoken to, the most important factor is the mite Varroa destructor. These mites feed onsuck up haemolymph (‘bee-blood’) thereby weakening the bees, while also spreading serious diseases like the deformed wing virus. Beekeepers stressed that the first and most important step to save the bees should be to control V. destructor more effectively. Currently, in the Netherlands and other European countries, beehives are treated against V. destructor with a combination of organic products such as thymol, formic acid and oxalic acid. During our conversations with beekeepers they mentioned that such compounds can be harmful to bees and humans when too high concentrations are used. On the other hand, too low concentrations fail to kill the mites and may facilitate resistance. Additionally, these compounds can contaminate the beeswax and the honey. We propose a Varroa specific treatment through the use of engineered bacteria. The bacteria will produce a mite specific toxin that is not harmful to bees nor humans. To do so, the bacteria will employ a network of regulation mechanisms to produce the toxin only when mites are present and when enough bacteria are present to effectively kill the mite. Other mechanisms are intended to strictly confine the bacteria to the treated hive, preventing them from spreading and mixing with natural larger ecosystems.
Introduction
Varroa destructor
Bee T
Specificity
Regulation
Safety
References
