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Team:Imperial College London/Human/Containment
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| + | The containment device is based on a toxin/anti-toxin system taken from the lysis cassette made by the Berkeley 2008 team. This originally involved the secretion of holin along with lysozyme, so that the holin would form pores in the inner membrane and allow the lysozyme to break down the cell wall. This will cause the cell to lyse when the inducible promoter was induced by arabinose. | ||
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| + | Also included in this cassette is the gene for antiholin, under the control of a weak, constitutive promoter to prevent any leakage. | ||
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| + | Our project takes this a step further. By using the anti-holin's ability to inhibit the activity of holin, we can create a system in which the lytic activity of holin can be negated by the presence of antiholin in certain cells. This means that we can make a plasmid that can kill one cell, but replicate in another. | ||
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Revision as of 17:33, 15 August 2011
Human Practices
Containment
To prevent spread of the auxin-producing plasmid in the environment, we have devised a containment device that will be able to kill other bacteria that take up the plasmid. In addition, we have devised experiments to test the survivability of E. coli in soil to evaluate whether these bacteria would be outcompeted by other soil microorganisms. Soil-dwelling protozoa also play an important role as they have been shown to feed off bacteria.
Soil Experiment
This experiment is designed to determine the survivability of E.Coli in soil. If bacteria were to be left in the soil we can estimate accurately the length of time they will be alive by carrying out this experiment. It is probable that the bacteria will live for longer in sterile soil than non-sterile soil, due to factors such as competition or they are being attacked by soil bacteria.
Results
Non-Sterile:
1A 0.315
1B 0.393
1C 0.361
2A 0.553
2B 0.583
2C 0.548
3A 0.399
3B 0.668
3C 0.300
Sterile
1A O.523
1B 0.548
1C 0.476
2A 0.716
2B 0.616
2C 0.664
3A 0.950
3B 0.887
3C 1.002
Containment Device
The containment device is based on a toxin/anti-toxin system taken from the lysis cassette made by the Berkeley 2008 team. This originally involved the secretion of holin along with lysozyme, so that the holin would form pores in the inner membrane and allow the lysozyme to break down the cell wall. This will cause the cell to lyse when the inducible promoter was induced by arabinose.Also included in this cassette is the gene for antiholin, under the control of a weak, constitutive promoter to prevent any leakage.
Our project takes this a step further. By using the anti-holin's ability to inhibit the activity of holin, we can create a system in which the lytic activity of holin can be negated by the presence of antiholin in certain cells. This means that we can make a plasmid that can kill one cell, but replicate in another.
