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Team:NYMU-Taipei/Project
From 2013.igem.org
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Overall project
The final goal of our research is to solve the Colony Collapse Disorder (CCD), which is a severe disease that causes bees to dramatically decline or disappear, in hope of protecting the eco-system, food supply and agricultural economy. Since the culprit of CCD is a kind of microsporidian called Nosema ceranae, we create Bee.coli to strengthen bees’ immune system and further ripe N. ceranae out.
The dormant stage of N. ceranae is a long-lived spore which is small enough to be ingested by bees through food or water. When N. ceranae travels to bees’ midgut, it will germinate polar filament to reach epithelial cells. Midgut cells are dominated by N. ceranae and bee’s ability to gain nutrition is thus decreased. In addition, some spores will come out in feces, leading to feces-oral or oral-oral infection in the beehive. N. ceranae is fatal to bees; however, so far there has been no efficient way to stop this pathogen. This year, we endow Bee. coli with multiple functions to resist the invasion of N. ceranae, hoping to cure CCD and prevent colonial infection thoroughly.
Bee. coli’s fuctions are designed to work sequentially. Before N. ceranae approaches midgut cells, Bee. coli will secrete mannosidase to inhibit N. ceranae from growing a polar filament. Epithelial cells will secrete ROS (reactive oxygen species) once being attacked by N. ceranae. ROS will activate OxyR promoter in Bee. coli, serving as the sign of N. ceranae invasion, eventually resulting in Bee. coli producing substances such as defensin and abaecin that can kill N. ceranae while being safe to bees and Bee. coli itself. Moreover, if the methods above unfortunately fail, Bee. coli will secrete ethanol to kill the single bee, that is to say, to sacrifice few infected bees in order to protect the healthy bees.
Considering the safety issue, Bee. coli is designed to commit suicide if it escapes from midgut. Once Bee. coli senses that the pH of the environment is different from that of midgut, Bee. coli will produce lysis protein and kill itself. Last but not the least, to make Bee. coli more practical, we choose the bacterial community naturally colonized in honeybees' gut, E.coli MG1655 included in the k-12 strain to enhance Bee. coli’s possibility of survival. We are trying to use encapsulation to transport Bee. coli to bee’s midgut. The beekeepers add capsules into water and then bees can consume Bee. coli through their diet. That way, Bee. coli can come into reality and solve the CCD problem.
