Team:Purdue/Safety/Safety

From 2014.igem.org

MineCrobe Safety Concerns

Bacillus subtilis is an endospore forming bacteria, which means that the bacteria goes into a hibernating state, becoming an ‘endospore’ , when environmental conditions are unfavorable. In this state, the bacteria can survive conditions including extreme heat, UV radiation exposure, and lack of nutrition.They’re nearly indestructible and practically immortal, able to survive for decades in this state. Endospores return to their normal bacterial state when conditions become favorable again. Endospores are resistant to most chemicals which would kill other cells, including detergents and alcohols, and can survive high temperatures for long periods of time, including boiling water for hours. However, they can be killed by certain mixtures of bleach and alkylating agents and can be destroyed by autoclaving. Since our bacillus is genetically modified according to our specifications, a simpler solution can be developed: a killswitch.

MineCrobe has a lactose-dependent killswitch, which kills the cells without prompting them to “hide” in the endospore state, harming the plants and soil around them like bleach would, . However, due to the desire for a more highly controlled genetically modified organism, a more effective kill switch would need to be implemented for a final commercial product. One concern is that bacteria burrowed deep in the soil could elude lactose when sprayed onto fields.