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The second part (killing) worked really good, but the first part (swimming towards a certain target) didn't work out so good. | The second part (killing) worked really good, but the first part (swimming towards a certain target) didn't work out so good. | ||
But anyway, there are interesting implications in both parts I want to comment on. | But anyway, there are interesting implications in both parts I want to comment on. | ||
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'''''a) making bacteria swim in a certain direction''''' | '''''a) making bacteria swim in a certain direction'''''<br/> | ||
It is pretty well known in literature, that bacteria have certain so-called chemotaxis receptors [http://2008.igem.org/Team:Heidelberg/Project/Sensing] on their surface. These receptors are, in nature, used for recognizing attractand molecules (nutrition, i.e. sugar) or repellents (i.e. toxic molecules). | It is pretty well known in literature, that bacteria have certain so-called chemotaxis receptors [http://2008.igem.org/Team:Heidelberg/Project/Sensing] on their surface. These receptors are, in nature, used for recognizing attractand molecules (nutrition, i.e. sugar) or repellents (i.e. toxic molecules). | ||
It is possible to influence (I would not say control, but at least strongly influence) the direction in that bacterial colonies on an agar plate swim by putting repellent and attractand molecules at different points on the plate. To give you one example: If I would put aspartate in the middle of an agar plate with E. coli colonies on it, the E. coli would move in direction of the aspartate. Their are different E. coli strains, that do contain different or even no receptors. Find a comparisn of swimming and not-swimming bacteria [http://parts.mit.edu/igem07/images/f/f3/SwarmingPic.jpg here]. | It is possible to influence (I would not say control, but at least strongly influence) the direction in that bacterial colonies on an agar plate swim by putting repellent and attractand molecules at different points on the plate. To give you one example: If I would put aspartate in the middle of an agar plate with E. coli colonies on it, the E. coli would move in direction of the aspartate. Their are different E. coli strains, that do contain different or even no receptors. Find a comparisn of swimming and not-swimming bacteria [http://parts.mit.edu/igem07/images/f/f3/SwarmingPic.jpg here]. | ||
In general that could be interesting if you wanted to make bacteria swim toward each other. To give you an impression on what swimming bacteria on a plate would look like, | In general that could be interesting if you wanted to make bacteria swim toward each other. To give you an impression on what swimming bacteria on a plate would look like, here some examples from my bachelor thesis [[media:Bacheloararbeit_Dominik_Niopek_druck.pdf]]. In the center assays, I just put bacteria on either site of the plate. As you can see, the swim rings of the two bacterial colonies meet in the middle after 24 hours (even faster). In the centerline assay I spottet immobilized bacteria in one line in the middle, and mobile bacteria again on either site of the line. | ||
Those so called swarm assays or swarm agar plates are really simple to prepare, easy to use. If you used different bacteria expressing color pigments (red, green, black), I am sure you could see how one bacteria would take over the space of the others, mix up with them, kill them etc. | |||
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'''''b) making bacteria kill other bacteria''''' | |||
In 2008 we also developed a killing mechanism which worked pretty good. The principle is the following: One bacterial strain was engineered to secrete a certain messenger molecule, called Autoinducer-1. The other bacterial strain was engineered to recognize Autoinducer-1 and thereby activate the production of a bacterial toxin called colicin [http://2008.igem.org/Team:Heidelberg/Project/Killing_II]. This means: If both bacterial strains are nearby each other, the one would start to kill the other. It is no problem to label on bacterial strain in red and the other in green and to visualize how the green bacteria die if they are nearby the red ones (figure 17 again on [http://2008.igem.org/Team:Heidelberg/Project/Killing_II this] page). The same should also be possible on agar swarm plates. | |||
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With swimming bacteria on swarm agar plates, you have many options to play around, as their are so many different bacterial strains (swimming slower, faster, not at all, recognizing substances etc.). Take this just as some general comments to think about. In case their is something in that comments, that interests you in particular, please don't hesitate to shoot me an e-mail. As I did my bachelor thesis on this topic (swimming bacteria), I would be very happy to provide all necessary information and help. | |||
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--[[User:Dniopek|Dniopek]] 23:18, 9 June 2010 (UTC) | |||
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====Go with the flow==== | ====Go with the flow==== | ||