Difference between revisions of "Team:NAWI Graz/Description"

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         <h2 class="section-sub">Introduction</h2>
 
         <h2 class="section-sub">Introduction</h2>
 
         <div class="section-text container">
 
         <div class="section-text container">
             An important area at the cutting edge of technology is the integration of biological systems in mechanical and automated
+
             An important area at the cutting edge of technology is the integration of biological systems in mechanical and automated systems. For our iGEM project we therefore chose to take a new approach on the integration of biology into technology. Our goal is the creation of a bacteria computer interface that acts in a constant feedback loop. We create a pH-sensitive <i>E. coli</i> strain that expresses detectable proteins according to a pH-level. The pH-level is determined by the position of a mobile robot in an arena with a virtual pH-gradient. The pH-level indicated by the robot's position is passed on to a bacterial culture in a bioreactor. As a response to the pH-shift, a shift in fluorescence protein expression is received due to the pH-sensitive promoters alx and asr. This altered expression correlates with a change in color, that is detectable with an optical system. The data from the optical signal is then send back to the robot resulting in a response in form of a directional change. Thus, we can control the motion of the robot through the arena with a constant feedback loop to the bioreactor.
            systems. For our iGEM project we therefore chose to take a new approach on the integration of biology into technology.
+
 
            Our goal is the creation of a bacteria computer interface that acts in a constant feedback loop. We create a
+
            pH sensitive E. coli strain that expresses detectable proteins according to a pH level. The pH level is determined
+
            by the position of a mobile robot in an arena with a virtual pH gradient. The pH level of the robot's position
+
            is passed on to bacteria that grow in a bioreactor, as a response to the pH shift, a shift in protein expression
+
            is made due to pH sensitive promoters. This altered expression correlates with a change in color, due to a change
+
            in expression, that is detectable with an optical system. The data from the optical signal is then send back
+
            to the robot resulting in a response in form of a directional change. Thus, we can control the motion of the
+
            robot through the arena with a constant feedback loop to the bioreactor. Furthermore, it is planned, to characterize
+
            and develop one of the used pH sensitive promotors, as a Biobrick.
+
 
         </div>
 
         </div>
 
     </div>
 
     </div>
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         <h2 class="section-sub">Detailed Project Description</h2>
 
         <h2 class="section-sub">Detailed Project Description</h2>
 
         <div class="section-text container">
 
         <div class="section-text container">
            It is planned to design a pH-sensitive E. coli strain with two different plasmids. Each of the plasmids contains a pH sensitive
+
          We designed two different pH-sensitive plasmids, which are transformed in an E.coli strain. Each of the plasmids contains a pH-sensitive promoter. The promoters are induced by different pH-levels. An acidic pH leads to the expression of a red fluorescent protein (mCardinal) and an alkaline pH to a green fluorescent protein (mNeonGreen).  
            promotor. The promotors are induced by different pH levels. An acidic pH leads to the expression of a red fluorecent
+
Both fluorescent proteins contain a N-terminal TEV-site followed by a F-degron. The TEV-site allows the degradation by the TEV-protease. Once the TEV-site is cleaved off, the F-degron can be recognized by the endogenous ClpAP-machinery. This ClpAP-machinery induces the degradation of the fluorescent proteins and enables a faster change in fluorescence, when a pH-shift occurs. This addition could be beneficial in the future to avoid accumulation of fluorescence protein, if you plan to use the same bacterial culture for an extended amount of time. Therefore, the TEV-protease will be integrated into the genome by CRISPR/Cas9, a novel method for gene-editing.  
            protein and an alkaline pH to a green fluorecent protein. Both fluorecent proteins contain a N-terminal TEV-site
+
The fluorescent signals are detected by a camera, leading to maneuvering the robot through an arena. Depending on the fluorescent color of the media, the robot turns either left or right.
            followed by a F-degron. The TEV-site, which allows the degradation by the TEV-protease. The F-degron should increase
+
 
            the velocity of the degradation of the fluorecent protein by recruiting endogenous ClpAP machinery. This is important
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            to provide a faster color change due to pH shift. The TEV-protease is integrated into the genome by CRISPR/Cas9.
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            Due to the assay, it is necessary that the proteins are produced and degraded very fast. Therefor, the protein
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            exhibits a quick maturation time. Based on the combination of the TEV-protease and a quick maturation time, it
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            is possible to gain rather quick changes of the fluorescence in the media. The fluorescent signals are detected
+
            by a camera, leading to maneuvering the robot through an arena. Depending on the fluorescent color of the media,
+
            the robot turns either left or right. For a better performance of transcription and expression the acid-inducable
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            asr-promotor should be characterized and further developed. Therefor, it is planned to mutate some regions, like
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            the RBS (ribosome binding site) of the promotor to optimized it.
+
 
         </div>
 
         </div>
 
     </div>
 
     </div>
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         <h2 class="section-sub">Applications and Implications</h2>
 
         <h2 class="section-sub">Applications and Implications</h2>
 
         <div class="section-text container">
 
         <div class="section-text container">
            One of the possible applications could be a bioreactor with bacteria that control their environment via active feedback.
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      One of the possible applications could be a bioreactor with bacteria that control their environment via active feedback. This enables the bacteria to give a signal, if they are in need for a different media composition. For example, if more nutrients or a switch of the pH level become necessary, bacteria will indicate it and a robot automatically adapts the medium to the circumstances. The technology also holds potential in the creation of reusable biosensors or a controlled bioremediation effort, where bacteria are mobile due to the connection to a robot host.
            Meaning that the bacterias give a signal, if they are in need for a different media composition, for example
+
            if more nutrients or a switch of the pH level become necessary bacteria indicate it and a robot automatically
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            adapts the medium to the circumstances. The technology also holds potential in the creation of reusable biosensors
+
            or a controlled bioremediation effort, where bacteria are mobile due to the connection to a robot host.
+
 
         </div>
 
         </div>
 
     </div>  
 
     </div>  

Revision as of 21:20, 30 October 2017

PROJECT DESCRIPTION


The aim of our project was to create a robot-bacteria interface, where information processing is done by a bacterial culture that exhibits a feedback loop with a mobile robot. To enable communication between bacteria and robot, we decided to engineer E. coli cells to respond to changes in pH with a change in fluorescence. To achieve pH-dependent expression of fluorescence protein, we used two different promoters: the acid-inducible asr promoter and the alkaline inducible alx promoter.

Introduction

An important area at the cutting edge of technology is the integration of biological systems in mechanical and automated systems. For our iGEM project we therefore chose to take a new approach on the integration of biology into technology. Our goal is the creation of a bacteria computer interface that acts in a constant feedback loop. We create a pH-sensitive E. coli strain that expresses detectable proteins according to a pH-level. The pH-level is determined by the position of a mobile robot in an arena with a virtual pH-gradient. The pH-level indicated by the robot's position is passed on to a bacterial culture in a bioreactor. As a response to the pH-shift, a shift in fluorescence protein expression is received due to the pH-sensitive promoters alx and asr. This altered expression correlates with a change in color, that is detectable with an optical system. The data from the optical signal is then send back to the robot resulting in a response in form of a directional change. Thus, we can control the motion of the robot through the arena with a constant feedback loop to the bioreactor.

Detailed Project Description

We designed two different pH-sensitive plasmids, which are transformed in an E.coli strain. Each of the plasmids contains a pH-sensitive promoter. The promoters are induced by different pH-levels. An acidic pH leads to the expression of a red fluorescent protein (mCardinal) and an alkaline pH to a green fluorescent protein (mNeonGreen). Both fluorescent proteins contain a N-terminal TEV-site followed by a F-degron. The TEV-site allows the degradation by the TEV-protease. Once the TEV-site is cleaved off, the F-degron can be recognized by the endogenous ClpAP-machinery. This ClpAP-machinery induces the degradation of the fluorescent proteins and enables a faster change in fluorescence, when a pH-shift occurs. This addition could be beneficial in the future to avoid accumulation of fluorescence protein, if you plan to use the same bacterial culture for an extended amount of time. Therefore, the TEV-protease will be integrated into the genome by CRISPR/Cas9, a novel method for gene-editing. The fluorescent signals are detected by a camera, leading to maneuvering the robot through an arena. Depending on the fluorescent color of the media, the robot turns either left or right.

Applications and Implications

One of the possible applications could be a bioreactor with bacteria that control their environment via active feedback. This enables the bacteria to give a signal, if they are in need for a different media composition. For example, if more nutrients or a switch of the pH level become necessary, bacteria will indicate it and a robot automatically adapts the medium to the circumstances. The technology also holds potential in the creation of reusable biosensors or a controlled bioremediation effort, where bacteria are mobile due to the connection to a robot host.