Difference between revisions of "Team:FAFU-CHINA/Design"

Line 8: Line 8:
  
 
<body>
 
<body>
 +
 
    
 
    
 
    
 
    
Line 143: Line 144:
 
  <ul class="dropdown-menu">
 
  <ul class="dropdown-menu">
 
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/Design">Design</a></li>
 
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/Design">Design</a></li>
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/Applied_Design">Background</a></li>
+
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/Background">Background</a></li>
 
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/InterLab">Interlab</a></li>
 
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/InterLab">Interlab</a></li>
 
<li class="chooseone"><a href="https://2017.igem.org/Team:FAFU-CHINA/Plan">Module 1: Phyto-route</a></li>
 
<li class="chooseone"><a href="https://2017.igem.org/Team:FAFU-CHINA/Plan">Module 1: Phyto-route</a></li>
Line 189: Line 190:
 
</li>-->
 
</li>-->
 
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/Model">Model</a></li>
 
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/Model">Model</a></li>
<li class="active"><a href="https://2017.igem.org/Team:FAFU-CHINA/Human_Practices">Human Practice</a></li>
+
<li><a href="https://2017.igem.org/Team:FAFU-CHINA/Human_Practices">Human Practice</a></li>
 
<li class="dropdown">
 
<li class="dropdown">
 
  <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Team <span class="caret"></span></a>
 
  <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Team <span class="caret"></span></a>
Line 203: Line 204:
  
  
<style>
+
<style type="text/css">
.wzdd{
+
.children{font-weight: bold; font-size: 100px;text-align: center;   font-family: monospace;}
margin:-100px auto 0;
+
p{font-family: -webkit-pictograph;
width:60%;
+
margin-left: 150px;
font-family: 'Open Sans', sans-serif;
+
margin-right: 150px }
padding-left:50px;
+
h2{color: #6a8d2c ;margin-top:100px;margin-left: 150px;
padding-right:50px;
+
margin-right: 150px ;font-family: -webkit-body;}
background-color: #F1E6CE;
+
}
+
 
</style>
 
</style>
<div class="wzdd">
+
<div style="background-color: #F1E6CE; width:80%; margin:-100px auto 0;"><br/><br/><br/><br/><br/><br/><br/><br/>
<br/><br/><br/><br/><br/><br/><br/><br/><br/><br/>
+
<div style=" margin-bottom:-120px;">
<h1>Communication with Entrepreneur</h1>
+
<!--<img style="transform:rotate(-90deg);width: 50%
<br/><p><strong>iGEM group:According to your years of field investigation and research, from what specific origins the heavy metal pollution arises? And by what means the heavy metal pollutes soil?</strong> </p>
+
src="back.png">-->
 
+
<h2 class="children" style="color:#6a8d2c ">Design </h2>
<p><strong>President Shi: </strong> At present, the metals that caused serious pollution include Cd, Pb and Hg. The enrichment of Cd in soil makes some crops, especially rice, excessive in the amount of heavy metal, which is actually what we call “Cd-polluted-rice”. The phenomenon is caused by the utilization of a kind of quick acting fertilizer, urea, in great amount, which can increase rice yield. When the massive loss of nutrient occurs in soil, a great amount of silicon-calcium-magnesium fertilizer will be used as soil conditioner to alleviate the trouble. But the problem is that the raw materials of such fertilizer are the by-products of cadmium and steel chippings in steel production. To lower costs, the steel chippings are used in the fertilizer before they are processed consciously with pertinent technologies, and thereby becoming one of the largest pollution sources of the poisonous heavy metal, cadmium. </p>
+
<hr style="border:1px solid #D4CCCC; clear:both;width: 80%;    margin: 0 auto"/>
 
+
<h2 style="color: #6a8d2c ;margin-top:100px;margin-left: 150px;
 
+
margin-right: 150px ;font-family: -webkit-body;">Ideas</h2>
<p>And the main source of mercury is the improper disposal of municipal waste. The best method to dispose municipal waste currently is incineration. But landfill remains to the major method to dispose the largest proportion of municipal waste, and the steps of disposal do not include filtration and classification, for which the pollution sources like waste batteries that are rich in mercury enter groundwater or are used in cheap organic fertilizers. The other source comes from the disposal of municipal sludge. In effect, a sharp contradiction has arisen between the increasing volume of sludge in China and its serious weakness in disposal, backwardness in disposal approach. A great deal of sludge is transported out, dumped or filed up at random, causing the “sludge-surrounding” phenomenon in many cities. And the waste containing mercury from daily life can cause secondary pollution by entering sewage system. <em>Guangzhou Daily</em> reported in 2009 that a cleaning company piled sludge in a forest farm locating between TangShalin village and ZhangMuTou forest farm, and then the heavy metal in the sludge infiltrated into a fishpond, which killed 15,000 kilograms of living fish. </p>
+
<p style="font-size: 20px ;margin-top:50px">For Human Practice, we found out that activities such as unpreceded use of agrochemicals and long-term application of urban sewage sludge, industrial waste disposal, waste incineration are the main sources of heavy metal in agricultural soil. While remediation of heavy metal in contaminated soil is done by physical and chemical processes which are costly and non-sustainable.  
 
+
<p>The pollution source of lead generally comes from the waste water and chippings leaked by paper mills in the upper reaches of urban water system. The waste that is excessive in lead is used in the production of cheap organic fertilizers, which will enter soil system once again. </p>
+
 
+
<p>In addition to the pollution sources above, the raw material used in the production of cheap inorganic salt, magnesium sulfate, is the waste sulfuric acid from galvanizing plants; glyphosate acid in the waste liquid from the production of herbicide, glyphosate, is recycled before being disposed properly, which constitutes another important pollution source. </p>
+
<img src="https://static.igem.org/mediawiki/2017/5/50/T--FAFU-CHINA--IMG_2017.JPG" style="width:50%"/>
+
<p style="font-size:5px; width:50%">Fig. 1 During this visit to Zhangzhou, we exchanged opinions and discussed on the project’s background, thinking pattern and some problems in practice with the president Shi Jinsheng in Fujian Kunsheng Agriculture.</p>
+
 
+
 
+
<br/><p><strong>iGEM group:Can you make some comments and suggestions after hearing our thinking pattern of the project?</strong> </p>
+
 
+
<p><strong>President Shi:</strong> As a matter of fact, we tend to apply micro-molecular humid acid or organic fertilizers of amino acid in practical utilization to fix or mobilize the necessary soil elements for plant’s growth. But the problem is: helpful and harmful elements will be fixed or mobilized simultaneously in the process, and thereby making it impossible to carry out a precise and peculiar selective fixation/mobilization. In your project, the heavy metal pollution is handled by the joint application of peculiar metal transporter protein and hyperaccumulator, which is pretty good. </p>
+
<img src="https://static.igem.org/mediawiki/2017/2/27/T--FAFU-CHINA--IMG_2028.JPG" style="width:50%"/>
+
 
+
 
+
<br/><p><strong>iGEM group:If our project needs to be applied in practice, what will be the specific operation processes? And of what aspects shall we be conscious?</strong> </p>
+
 
+
<p><strong>President Shi: </strong>Generally speaking, phosphate solubilizing bacteria will be subject to a series of courses to rejuvenate and ferment, and then be colonized in the plant root as the added substance of organic fertilizers. That can control the reproduction of harmful bacteria in soil effectively on one hand and disintegrate phosphorus and potassium on the other hand. In addition to organic fertilizers, something like fermentation liquor of cane sugar, fermentation liquor of alginic salts, etc, is also a good carrier. It is to guarantee an adequate carbon source and nitrogen source that matters. Talking about the aspect you should very care about is safety. Currently, it is unclear whether the unmonitored release of every genetically engineered microbe(GEM) into the enviroment is absolutely harmful or absolutely safe, especially your project, which actually is referring to GMO that has been controversial for almost 20 years in China, even world. Decades of scientific research and changes in government polices may be needed to determine and define the danger or safety of every type of GEM, as current information is sparse. </p>
+
 
+
</div>
+
 
+
 
+
 
+
 
+
  
 +
In this case, we planned to combat heavy metal pollution problem in the soil through the alliance between microbe and plant, by manufacturing our chassis——<i>Bacillus megaterium</i>through getting the different complement of metal-binding proteins that handle metals inside cell as a metal-trap to alleviate metal stress of phytoremediation.
 +
</p>
 +
<br/><br/><br/>
 +
<hr style="border:1px solid #D4CCCC; clear:both;width: 80%; margin: 0 auto"/>
 +
<h2 style="color: #6a8d2c;">Metal-binding proteins </h2>
 +
<p style="font-size: 20px;margin-top:50px">Our alleviating system refers to two kinds of metal binding proteins-MT and MBP derived from 2014 Cornell and 2010 Peking University Biobricks respectively.</p>
 +
<p style="font-size: 20px;margin-top:50px">MTs(metallothioneins)-are low-molecular weight, cysteine-rich metal-binding proteins found in wide variety of organisms including bacteria, fungi and all eukaryotic plant and animal species. MTs contain 61-62 amino acids and are structually composed of two globular metal-binding domains(α and β) with metal ion. The C-terminal α domain contains 11 cysteines and the N-terminal β domain contains 9 cysteines. The 20 cysteine residues in MTs allow it to bind up to a total of 7 cadmium ions.[1]Several systems have been developed to allow for stable construction and high level expression of recombinant proteins in bacteria. To avoid being degradated by proteolytic enzyme, the expression of MT in frame with GST allows for stable expression. Im previous research, the fusion protein was prone to increase metal ion sequestration in <i>E.coli</i>, this time we intended to try to express fusion protein in our chassis.</p>
 +
<p style="text-align: center"><img src="https://static.igem.org/mediawiki/2017/8/82/T--FAFU-CHINA--gst.png" style="width:35%;border-radius:20px 20px 20px 20px"/></p>
 +
<p style="font-size: 15px;text-align: center">This figure is engineered metal binding domain of MerR family.( Protein structure constructed by <a href="https://2017.igem.org/Team:BNU-China/Collaborations"/>BNU</a>)</p>
 +
<p style="font-size: 20px;margin-top:50px">MBP(engineered from PbrR and MerR respectively)-PbrR and MerR are members of the MerR family of metal-sensing regulatory protein, acts a effective Pb(II) and Hg (II) capturer respectively. According to earlier research, the DNA binding domain and metal binding domain can function individually and the constructed peptide can form a stable dimer with its mercury and lead binding affinity remaining. In order to reduce side effects of over-expression, Peking University tandemed two copies of metal binding domain of MerR and PbrR.</p>
 +
<p style="text-align: center"><img src="https://static.igem.org/mediawiki/2017/4/4c/T--FAFU-CHINA--MBP.png" style="width:35%;border-radius:20px 20px 20px 20px"/></p>
 +
<p style="font-size: 15px;text-align: center">This figure is 3D structure of GST-MT.( Protein structure constructed by <a href="https://2017.igem.org/Team:BNU-China/Collaborations"/>BNU</a>)
 +
</p>
 +
<p style="font-size: 20px;margin-top:50px">Previous research showed that different localizations affect metal biosorption capability. [2]In this regard, MBPs were expressed in either the periplasmic and outer membrane by using DsbA and Lpp-Omp fusion partner respectively.</p>
 +
<br/><br/><br/>
 +
<hr style="border:1px solid #D4CCCC; clear:both;width: 80%; margin: 0 auto"/>
 +
<h2 style="color: #6a8d2c;">ACC deaminase </h2>
 +
<p style="font-size: 20px;margin-top:50px">High levels of ethylene, produced under stressed conditions, can inhibit certain processes such as root elongation. 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which regulates ethylene production by metabolizing ACC (an immediate precursor of ethylene biosynthesis in higher plants) into α-ketobutyrate and ammonia,simultaneously enhances plant growth and biomass by P solubilization and uptake particularly under stress condition by heavy metals. In our project, we aimed for increasing ability of transgenic plants expressing the bacterial enzyme ACC deaminase to accumulate heavy metals.</p>
 +
<br/>
 +
<p style="text-align: center"><img src="https://static.igem.org/mediawiki/2017/6/63/T--FAFU-CHINA--tonglutu.png" style="width:49%;border-radius:20px 20px 20px 20px"/></p>
 +
<br/><br/><br/>
 +
<hr style="border:1px solid #D4CCCC; clear:both;width: 80%; margin: 0 auto"/>
 +
<h2 style="color: #6a8d2c;">Summary</h2>
 +
<p style="font-size: 20px;margin-top:50px">We hope to establish a sustainable, regulable and reusable project to solve the soil polluted by heavy metals. Phosphate-solubilizing bacteria have important functions. In our project, we used the mechanism of the alliance between microbe and plant, by manufacturing <i>Bacillus megaterium</i>, which is a kind of phosphate-solubilizing microorganism exists in the root system, forcing it enhance the plant remediation from two aspects, accumulating heavy metals and defend adversity stress. To achieve the goal of spatial specificity, we make most of the expression system which is regulated by root organic acid. We also used MBP (metal binding protein) and ACC deaminase to make accumulation of heavy metal in root system’s soil success. Finally, heavy metals will transfer to plant itself. A series of transformation we made in phosphate-solubilizing bacteria in our project will solve the weakness of hyper-accumulators, therefore, the remediation method will be put into use widely.</p>
 +
<br/><br/><br/>
 +
<hr style="border:1px solid #D4CCCC; clear:both;width: 80%; margin: 0 auto"/>
 +
<h2 style="color: #6a8d2c;">reference</h2>
 +
<p style="font-size: 17px;margin-top:50px">[1]Haq, F., Mahoney, M., & Koropatnick, J. (2003). Signaling events for metallothionein induction, 533, 211–226.</p>
 +
<p style="font-size: 17px;margin-top:25px">[2]Kao, W., Chiu, Y., Chang, C., & Chang, J. (2006). Localization Effect on the Metal Biosorption Capability of Recombinant Mammalian and Fish Metallothioneins in Escherichia coli, 1256–1264.
 +
</p>
 +
<br/><br/><br/><br/><br/><br/>
 
</body>
 
</body>
 
</html>
 
</html>

Revision as of 08:57, 28 October 2017









Design


Ideas

For Human Practice, we found out that activities such as unpreceded use of agrochemicals and long-term application of urban sewage sludge, industrial waste disposal, waste incineration are the main sources of heavy metal in agricultural soil. While remediation of heavy metal in contaminated soil is done by physical and chemical processes which are costly and non-sustainable. In this case, we planned to combat heavy metal pollution problem in the soil through the alliance between microbe and plant, by manufacturing our chassis——Bacillus megateriumthrough getting the different complement of metal-binding proteins that handle metals inside cell as a metal-trap to alleviate metal stress of phytoremediation.





Metal-binding proteins

Our alleviating system refers to two kinds of metal binding proteins-MT and MBP derived from 2014 Cornell and 2010 Peking University Biobricks respectively.

MTs(metallothioneins)-are low-molecular weight, cysteine-rich metal-binding proteins found in wide variety of organisms including bacteria, fungi and all eukaryotic plant and animal species. MTs contain 61-62 amino acids and are structually composed of two globular metal-binding domains(α and β) with metal ion. The C-terminal α domain contains 11 cysteines and the N-terminal β domain contains 9 cysteines. The 20 cysteine residues in MTs allow it to bind up to a total of 7 cadmium ions.[1]Several systems have been developed to allow for stable construction and high level expression of recombinant proteins in bacteria. To avoid being degradated by proteolytic enzyme, the expression of MT in frame with GST allows for stable expression. Im previous research, the fusion protein was prone to increase metal ion sequestration in E.coli, this time we intended to try to express fusion protein in our chassis.

This figure is engineered metal binding domain of MerR family.( Protein structure constructed by BNU)

MBP(engineered from PbrR and MerR respectively)-PbrR and MerR are members of the MerR family of metal-sensing regulatory protein, acts a effective Pb(II) and Hg (II) capturer respectively. According to earlier research, the DNA binding domain and metal binding domain can function individually and the constructed peptide can form a stable dimer with its mercury and lead binding affinity remaining. In order to reduce side effects of over-expression, Peking University tandemed two copies of metal binding domain of MerR and PbrR.

This figure is 3D structure of GST-MT.( Protein structure constructed by BNU)

Previous research showed that different localizations affect metal biosorption capability. [2]In this regard, MBPs were expressed in either the periplasmic and outer membrane by using DsbA and Lpp-Omp fusion partner respectively.





ACC deaminase

High levels of ethylene, produced under stressed conditions, can inhibit certain processes such as root elongation. 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which regulates ethylene production by metabolizing ACC (an immediate precursor of ethylene biosynthesis in higher plants) into α-ketobutyrate and ammonia,simultaneously enhances plant growth and biomass by P solubilization and uptake particularly under stress condition by heavy metals. In our project, we aimed for increasing ability of transgenic plants expressing the bacterial enzyme ACC deaminase to accumulate heavy metals.






Summary

We hope to establish a sustainable, regulable and reusable project to solve the soil polluted by heavy metals. Phosphate-solubilizing bacteria have important functions. In our project, we used the mechanism of the alliance between microbe and plant, by manufacturing Bacillus megaterium, which is a kind of phosphate-solubilizing microorganism exists in the root system, forcing it enhance the plant remediation from two aspects, accumulating heavy metals and defend adversity stress. To achieve the goal of spatial specificity, we make most of the expression system which is regulated by root organic acid. We also used MBP (metal binding protein) and ACC deaminase to make accumulation of heavy metal in root system’s soil success. Finally, heavy metals will transfer to plant itself. A series of transformation we made in phosphate-solubilizing bacteria in our project will solve the weakness of hyper-accumulators, therefore, the remediation method will be put into use widely.





reference

[1]Haq, F., Mahoney, M., & Koropatnick, J. (2003). Signaling events for metallothionein induction, 533, 211–226.

[2]Kao, W., Chiu, Y., Chang, C., & Chang, J. (2006). Localization Effect on the Metal Biosorption Capability of Recombinant Mammalian and Fish Metallothioneins in Escherichia coli, 1256–1264.