Biosafety System

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 by damage or incorrect handling. In order to counter this problem there exist useful systems to prevent the bacteria from escaping or killing the bacteria when they are outside of the application. To complement this archive we constructed not only one system but also three systems which differ in leakiness and strength. For this approach we combined two common Biosafety-ideas, an auxotrophy and a toxic gene product, in one device. So the constructed Biosafety-System takes the best of this two approaches and is characterized by a double kill-swtich system. This double kill-switch mechanism provides additional a higher plasmid stability and a higher resistance towards undesirable mutations. In one sentence: Our Biosafety-System is save!

Theory

TetOR Alive

System M in the MFC: In this case the mikroorganism is in the MFC with sufficient L-rhamnose. It comes to an expression of TetR which blocks TetO by binding and alr which switches L-alanine to D-alanine. Because of the fact that TetR blocks TetO the RNase Ba can't expressed.

System M outside of the MFC: In this case the mikroorganism could get out of the MFC by damage or incorrect handling. Outside of the MFC there isn't enough L-rhamnose. So TetR doesn't block TetO anymore so the degradation process is induced by activating the TetO and the ensuing expression of RNase Ba. E.coli dies.

Lac of growth

System L in the MFC: In this case the mikroorganism is in the MFC with sufficient L-rhamnose. It comes to an expression of lacI which blocks the lac-promoter by binding and alr which switches L-alanine to D-alanine. Because of the fact that lacI blocks the lac-promoter the RNase Ba can't expressed.

System L outside of the MFC: In this case the mikroorganism could get out of the MFC by damage or incorrect handling. Outside of the MFC there isn't enough L-rhamnose. So... E.coli dies.

araCtive

System S in the MFC: In this case the mikroorganism is in the MFC with sufficient L-rhamnose. It comes to an expression of araC which blocks the arabinose-promoter by binding and alr which switches L-alanine to D-alanine. Because of the fact that araC blocks the arabinose-promoter the RNase Ba can't expressed.

System S outside of the MFC: In this case the mikroorganism could get out of the MFC by damage or incorrect handling. Outside of the MFC there isn't enough L-rhamnose. So araC doesn't block the arabinose-promotor any more and RNase Ba can be expressed.E.coli dies.

Results

References