Biosafety

Overview

Biosafety is an essential aspect when taking part in iGEM, especially when you work with living organisms which could possibly get out of your application due to damage or incorrect handling. It is important to protect the population and the environment by developing and applying systems which address these aspects. There already exist several useful systems which prevent the bacteria from escaping or kill them when they are outside of the device. To complement this we constructed three systems which differ in leakiness and strength. We combined two common Biosafety ideas, an auxotrophic and a toxic gene product, in one device. Thereby the constructed Biosafety system takes the best parts of these two approaches and is therefore characterized as a double kill-switch system. This double kill-switch mechanism provides higher plasmid stability and additionally higher resistance towards undesirable mutations. In short: Our Biosafety-System is safe!

Application

Biosafety of the MFC is based on several layers. First of all, the device we designed is a closed system, thus preventing the escape of E. coli into the environment. If the physical containment, i.e. the MFC, is breached, lack of proper inducers which should be absent in the environment, results in the production of a toxic protein. This toxic protein is called Barnase, a RNase of Bacillus amyloliquefaciens which degrades the RNA and causes the cell death. Finally, presence of a plasmid encoded alanine racemase in E. coli strains lacking a chromosomal copy of this enzyme enforces plasmid stability without the need of additional antibiotics. Because of the fact that expensive antibiotics aren’t necessary any more in the systems it makes them more economic. All in all this aspects make the individual systems very safe and usable outside of the laboratory. To assess the usability of our MFC regarding potential applications, we searched for a feasibility study and compared it to our results. It shows, that our currently achieved efficiencies have the potential for efficient energy production in real world applications.
Not only the currently used applications are important but also the future applications. For detailed information about using the MFC in actual and future applications see our Application site.