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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 chemotaxis receptors or even no receptors. Furthermore, there are bacteria that swim fast, slow or bacteria that can't even swim at all. 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 chemotaxis receptors or even no receptors. Furthermore, there are bacteria that swim fast, slow or bacteria that can't even swim at all. 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, 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. | 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, ie. 6 or 12 hours, depends on the bacteria). 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. | 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. | ||