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Team:UCL/Project/About
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| - | </div> | + | <img src="https://static.igem.org/mediawiki/2014/3/3c/OAbout_Bannero.jpg" width="100%" height="100%" alt="About Our Project" /> |
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| + | <div id="BPimagewrapperHeader" data-step="1" data-position='top' data-intro="This is the first section, introducing the problem we are solving."> | ||
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| + | <div class="textArena"> | ||
| + | <h1>The Problem: Azo Dyes in the environment</h1> | ||
| + | <p class="infoBlock1 cf" data-step="2" data-position='top' data-intro="Read up on the basics of azo dye: history, usage, and concerns."> | ||
| + | <a data-tip="true" class="top large" data-tip-content="This is Sir William Henry Perkin, who accidentally discovered azo dyes in 1853 at the age of 15. He discovered mauveine (the first synthetic organic chemical dye) whilst working on quinine synthesis." href="javascript:void(0)" style="width: 13%;float: left;margin-right:2%"><img src="https://static.igem.org/mediawiki/2014/9/95/William-henry-perkin.jpg" style="max-width: 100%;"></a> | ||
| + | Since their accidental discovery by Sir William Henry Perkin in 1853, azo dyes have become one of the most popular forms of <a data-tip="true" class="top large" data-tip-content="Azo dyes can supply a complete rainbow of colours, but yellow/red dyes are more common than blue/brown dyes." href="javascript:void(0)"><b>synthetic colourant</b></a>. These dyes are currently used in the industrial manufacture of a variety of <a data-tip="true" class="top large" data-tip-content="Azo dyes account for approximately 60-70% of all dyes used in food and textile manufacture." href="javascript:void(0)"><b>products</b></a>, ranging from clothing and upholstery to cosmetics and tattoo ink, as well as many others.<br><br>Although azo-dyes are widely regarded as a safe and stable form of synthetic colourant, some of them can take on <a data-tip="true" class="top large" data-tip-content="Some azo dyes have been reported to cause human bladder cancer, splenic sarcomas and hepatocarcinomas as a result of azo dye reduction in the intestinal tract." href="javascript:void(0)"><b>dangerous properties</b></a> after they have been broken down by <a data-tip="true" class="top large" data-tip-content="The process of azo bond reduction is catalyzed by soluble cytoplasmic enzymes known as azoreductases." href="javascript:void(0)"><b>enzymes</b></a> in the guts of organisms.</p> | ||
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| + | <div class="infoBlock2 cf"> | ||
| + | <a data-tip="true" class="top large" data-tip-content="Exposure of fish (common carp) to dye containing effluent strongly affects their rate of feeding, absorption and conversion (Roopadevi and Somashkar, 2012)." href="javascript:void(0)" style="width: 60%;float: right;margin-left:2%"><img src="https://static.igem.org/mediawiki/2014/6/68/Theproblem.jpg" style="max-width: 100%;"></a> | ||
| + | <p data-step="3" data-position='top' data-intro="Here are some stats about dye pollution by industry."> | ||
| + | In the textile industry alone, the global annual production of dyes amounts to a <a data-tip="true" class="top large" data-tip-content="Azo dyes represent about 70% of this value on weight basis (Hao et al. 2000)" href="javascript:void(0)"><b>million metric tons</b></a>. In many countries, the leftover dye <a data-tip="true" class="top large" data-tip-content="It had been estimated that about 10-15% of the dye-stuff used during the dyeing process do not bind to fibers and are released in the effluent." href="javascript:void(0)"><b>effluent</b></a> produced by industrial manufacturers is often not properly disposed of, or removed, during water treatment. | ||
| + | </p><br> | ||
| + | <p data-step="4" data-position='top' data-intro="Read up on the environmental impacts of azo dye pollution.">This results in the <a data-tip="true" class="top large" data-tip-content="These compounds are designed to be stable against chemical and light induced oxidation, becoming highly persistent in nature. For instance, the half life of reactive blue 19 is about 46 years at pH 7 at 25ºC (Hao et al. 2000)." href="javascript:void(0)"><b>accumulation</b></a> of azo dyes in water bodies where they are then ingested by aquatic organisms. Additionally, irrigation of agricultural lands with dye polluted water severely affects soil fertility and <a data-tip="true" class="top large" data-tip-content="It affects different plant growth parameters namely | ||
| + | seed germination, chlorophyll content, root and shoot length (Ameta et al. 2003)." href="javascript:void(0)"><b>plant growth</b></a>.<br><br>The products of this enzymatic breakdown have been found to be both mutagenic and carcinogenic, and have been linked to increased occurrences of several different forms of cancer if they enter the food chain. Despite this toxicity and it's potential effect on human health, little to no effort has been made to dispose of these leftover azo dyes more responsibly.<br><br>As a result, development of remediation technologies for treatment of dye containing waste waters has been a matter of major concern for environmentalists. </p></div> | ||
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| + | <div class="textArena"> | ||
| + | <h1> The Solution: GoodBye Azo Dye, UCL iGEM 2014 </h1> | ||
| + | <p class="infoBlock2 cf"> | ||
| + | We have created an <b>Azo-Remediation Chassis (ARC)</b>, a complete synthetic azo dye decolourising device in <i>E. coli</i>. The ARC harnesses several different independent enzymes that degrade azo dyes and their breakdown products. This allows the development of a bioengineered process preventing accumulation of carcinogenic azo dye products in industrial wastewater. | ||
| + | </p> | ||
| + | <div id="BPimagewrapperHeader" data-step="6" data-position='top' data-intro="Here's an overview graphic of our E. Coli."><img src="https://static.igem.org/mediawiki/2014/4/46/Thesolutionandbreakdown.jpg" width="100%" alt="" /></div> | ||
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| + | <p class="infoBlock2 cf"> | ||
| + | The diagram above demonstrates how our <i>E. Coli</i> plasmid incorporates the following enzymes:<span style="color: #B36F6E; font-weight: bold"> Azoreductase from Pseudomonas Aeruginosa</span>,<span style="color: #A49D67; font-weight: bold "> Lignin Peroxidase from Phanaerochaete Chrysosporium</span>,<span style="color: #6D995E; font-weight: bold"> Azoreductase & Bacterial Peroxidase from Pseudomonas Putida</span>, and<span style="color: #5F6D9C; font-weight: bold "> Bacterial Peroxidase & Laccase from Bacillus Subtilis</span>. | ||
| + | </p> | ||
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| + | <b>Azoreductase from Pseudomonas Aeruginosa</b> | ||
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| + | </strong></div><div class="body"> | ||
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| + | <p><a style="width: 30%;float: right;margin-left:2%"><img src="https://static.igem.org/mediawiki/2014/8/80/UCLReactionPathway1.png" style="max-width: 90%;"></a> | ||
| + | Azoreductase from <i>Pseudomonas aeruginosa</i> is intended to work <b>complementary with azo dyes</b>, in order to cover a wider spectrum of dyes more efficiently. | ||
| + | <br><br> | ||
| + | The reaction pathway on the right demonstrates how azoreductase will <b>cleave the azo-bond (N=N)</b>, producing aromatic amines. However, these amines are highly toxic; hence we have incorporated further enzymes into our <b>ARC</b>. | ||
| + | </p><br><br><br><br> | ||
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| + | <b>Lignin Peroxidase from Phanaerochaete Chrysosporium</b> | ||
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| + | <p><a style="width: 30%;float: right;margin-left:2%"><img src="https://static.igem.org/mediawiki/2014/3/34/UCLiGEMReactionPathway2.png" style="max-width: 90%;"></a> | ||
| + | <b>Aromatic amines</b> produced by azoreductase cleavage are <b>oxidised</b>, resulting generally in a substitution of the amine groups by other oxygenated groups like carboxyls or carbonyls. | ||
| + | <br><br> | ||
| + | In this case, the oxidation will be carried out by Lignin Peroxidase from <i>Phanaerochaete Chrysosporium</i>. The mechanisms for these oxidations <b>vary from dye to dye</b>, hence we have incorporated laccase and other peroxidases into our <b>ARC</b>. | ||
| + | </p><br><br><br><br> | ||
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| + | <b>Azoreductase & Bacterial Peroxidase from Pseudomonas Putida</b> | ||
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| + | <p><a style="width: 30%;float: left;margin-right:2%"><img src="https://static.igem.org/mediawiki/2014/8/80/UCLReactionPathway1.png" style="max-width: 90%;"></a> | ||
| + | <a style="width: 30%;float: right ;margin-left:2%"><img src="https://static.igem.org/mediawiki/2014/3/34/UCLiGEMReactionPathway2.png" style="max-width: 90%;"></a> | ||
| + | Azoreductase from <i>Pseudomonas Putida</i> performs the <b>cleavage of the azo-bond (N=N)</b>, working in conjunction with Azoreductase from <i>Pseudomonas aeruginosa</i> - <b>maximising the efficiency of our ARC</b>. | ||
| + | <br><br> | ||
| + | Bacterial Peroxidase from <i>Pseudomonas Putida</i> performs the <b>oxidisation of the aromatic amines</b>, working in conjunction with Lignin Peroxidase from <i>Phanaerochaete Chrysosporium</i>. | ||
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| + | <b>Bacterial Peroxidase & Laccase from Bacillus Subtilis</b> | ||
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| + | </strong></div><div class="body"> | ||
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| + | <p><a style="width: 30%;float: right ;margin-left:2%"><img src="https://static.igem.org/mediawiki/2014/3/34/UCLiGEMReactionPathway2.png" style="max-width: 90%;"></a> | ||
| + | Bacterial Peroxidase & Laccase from <i>Bacillus Subtilis</i> performs the <b>oxidisation of the aromatic amines</b>, working in conjunction with Lignin Peroxidase from <i>Phanaerochaete Chrysosporium</i> and Bacterial Peroxidase from <i>Pseudomonas Putida</i> - <b>maximising the efficiency of our ARC</b>. | ||
| + | </p><br><br><br><br><br><br><br> | ||
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| + | <p> | ||
| + | A <a href="https://2014.igem.org/Team:UCL/Science/Bioprocessing"><b>bioprocess</b></a> employing the ARC in an industrial setting has been developed and various modes of operation explored. This may serve as an end-of-pipe, lucrative addition to facilities expelling azo dye contaminants. Furthermore, <a href="https://2014.igem.org/Team:UCL/Project/Xenobiology"><b>xenobiological</b></a> approaches to biosafety are considered and a proposal for an “azotrophic” organism paves the way for a new era in synthetic biology biosafety. | ||
| + | </p> | ||
| + | </div> | ||
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| + | <br> | ||
| + | <div class="SCJBBHIGHLIGHT" data-step="7" data-position='top' data-intro="Read up on our BioBricks, our lab team has been working hard to make our dreams a reality."> | ||
| + | <p class="infoBlock3 cf"> | ||
| + | <a href="https://2014.igem.org/Team:UCL/Project/Biobricks" data-tip="true" class="top large" data-tip-content="Click to learn more about our BioBricks!" href="javascript:void(0)" style="width: 18%;float: left;margin-right:2%"><img src="https://static.igem.org/mediawiki/2014/c/c3/Team_Icons-01.png" style="max-width: 100%;"></a>For our iGEM project we developed a process to <a data-tip="true" class="top large" data-tip-content="Our reaction pathway involves two steps. First, azo-bond cleavage, and then oxidation of aromatic amines." href="javascript:void(0)"><b>controllably degrade and detoxify</b></a> the excess azo dye effluent at the source - the textile factories - before they even reach the water systems. We achieved this goal by introducing the genes for three enzymes related to the degradation of these dyes: <a data-tip="true" class="top large" data-tip-content="Azoreductase will cleave the azo-bond (N=N) by a double reduction using NADPH as a cofactor, producing a series of highly toxic aromatic amines." href="javascript:void(0)"><b>azoreductase</b></a>, <a data-tip="true" class="top large" data-tip-content="The aromatic amines will then be oxidised, producing less toxic final products." href="javascript:void(0)"><b>laccase</b></a>, and <a data-tip="true" class="top large" data-tip-content="We will investigate the activity of lignin peroxidase in addition to laccase, to determine which is the optimum enzyme for our process." href="javascript:void(0)"><b>lignin peroxidase</b></a> into a host <i>E.coli</i> cell to create an enhanced azo dye decolourising organism.</p> | ||
| + | </div> | ||
| + | <br> | ||
| + | <div class="SCJBPHIGHLIGHT" data-step="8" data-position='top' data-intro="Read up on sustainable bioprocessing, a platform for future bioremediation engineering technologies."> | ||
| + | <p class="infoBlock4 cf"><a href="https://2014.igem.org/Team:UCL/Science/Bioprocessing" data-tip="true" class="top large" data-tip-content="Click to learn more about our bioprocess!" href="javascript:void(0)" style="width: 18%;float: right;margin-left:2%"><img src="https://static.igem.org/mediawiki/2014/b/be/Team_Icons-06.png" style="max-width: 100%;"></a>We also designed an <a data-tip="true" class="top large" data-tip-content="Our process could be implemented in water treatment facilities or within the dyeing industry itself." href="javascript:void(0)"><b>integrated end-of-pipe method</b></a> for detoxifying dye factory wastewater effluent streams by incorporating our engineered <i>E. coli</i> strain in a two-stage process to ensure optimal conditions for the degradation of azo dyes within a batch bioreactor system. The potential for scalability of this method would present various <a data-tip="true" class="top large" data-tip-content="As a financial incentive, we also looked at maximizing the profitability of various potential breakdown products as well as investigated the application of microbial fuel cell technology to an aerobic bioreactor system, for simultaneously detoxifying azo dyes and generating electricity." href="javascript:void(0)"><b>economic and environmental advantages</b></a> for industries that generate large amounts of dyestuff. The system we have developed could also be enhanced to become a <a data-tip="true" class="top large" data-tip-content="The development of such a process would be an attractive and effective approach to dealing with azo dye contamination of the environment." href="javascript:void(0)"><b>modular bioprocess method</b></a> for wastewater treatment of other toxic, normally recalcitrant chemicals.</p> | ||
| + | </div> | ||
| + | <br> | ||
| + | <div class="SCJPPHIGHLIGHT" data-step="9" data-position='top' data-intro="Last but not least, the people who made this all possible."> | ||
| + | <p class="infoBlock5 cf"><a href="https://2014.igem.org/Team:UCL/Humans/Team" data-tip="true" class="top large" data-tip-content="Click to learn more about us!" href="javascript:void(0)" style="width: 18%;float: left;margin-right:2%"><img src="https://static.igem.org/mediawiki/2014/b/ba/Team_Icons-03.png" style="max-width: 100%;"></a>This year, UCL has a highly interdisciplinary team of undergraduates and postgraduates, forming a <a data-tip="true" class="top large" data-tip-content="UCL has been involved in iGEM since 2009, and we have a community of eager minds craving for more iGEM and more synthetic biology." href="javascript:void(0)"><b>synbio community</b></a> at UCL. We are all genuinely delighted to be trying to bring synthetic biology to the world around us. This year we have accomplished immense public engagement and tackled key issues regarding policy and practices.</p> | ||
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Latest revision as of 02:32, 18 October 2014
The Problem: Azo Dyes in the environment
Since their accidental discovery by Sir William Henry Perkin in 1853, azo dyes have become one of the most popular forms of synthetic colourant. These dyes are currently used in the industrial manufacture of a variety of products, ranging from clothing and upholstery to cosmetics and tattoo ink, as well as many others.
Although azo-dyes are widely regarded as a safe and stable form of synthetic colourant, some of them can take on dangerous properties after they have been broken down by enzymes in the guts of organisms.
In the textile industry alone, the global annual production of dyes amounts to a million metric tons. In many countries, the leftover dye effluent produced by industrial manufacturers is often not properly disposed of, or removed, during water treatment.
This results in the accumulation of azo dyes in water bodies where they are then ingested by aquatic organisms. Additionally, irrigation of agricultural lands with dye polluted water severely affects soil fertility and plant growth.
The products of this enzymatic breakdown have been found to be both mutagenic and carcinogenic, and have been linked to increased occurrences of several different forms of cancer if they enter the food chain. Despite this toxicity and it's potential effect on human health, little to no effort has been made to dispose of these leftover azo dyes more responsibly.
As a result, development of remediation technologies for treatment of dye containing waste waters has been a matter of major concern for environmentalists.
The Solution: GoodBye Azo Dye, UCL iGEM 2014
We have created an Azo-Remediation Chassis (ARC), a complete synthetic azo dye decolourising device in E. coli. The ARC harnesses several different independent enzymes that degrade azo dyes and their breakdown products. This allows the development of a bioengineered process preventing accumulation of carcinogenic azo dye products in industrial wastewater.
The diagram above demonstrates how our E. Coli plasmid incorporates the following enzymes: Azoreductase from Pseudomonas Aeruginosa, Lignin Peroxidase from Phanaerochaete Chrysosporium, Azoreductase & Bacterial Peroxidase from Pseudomonas Putida, and Bacterial Peroxidase & Laccase from Bacillus Subtilis.
Azoreductase from Pseudomonas aeruginosa is intended to work complementary with azo dyes, in order to cover a wider spectrum of dyes more efficiently.
The reaction pathway on the right demonstrates how azoreductase will cleave the azo-bond (N=N), producing aromatic amines. However, these amines are highly toxic; hence we have incorporated further enzymes into our ARC.
Aromatic amines produced by azoreductase cleavage are oxidised, resulting generally in a substitution of the amine groups by other oxygenated groups like carboxyls or carbonyls.
In this case, the oxidation will be carried out by Lignin Peroxidase from Phanaerochaete Chrysosporium. The mechanisms for these oxidations vary from dye to dye, hence we have incorporated laccase and other peroxidases into our ARC.
Azoreductase from Pseudomonas Putida performs the cleavage of the azo-bond (N=N), working in conjunction with Azoreductase from Pseudomonas aeruginosa - maximising the efficiency of our ARC.
Bacterial Peroxidase from Pseudomonas Putida performs the oxidisation of the aromatic amines, working in conjunction with Lignin Peroxidase from Phanaerochaete Chrysosporium.
Bacterial Peroxidase & Laccase from Bacillus Subtilis performs the oxidisation of the aromatic amines, working in conjunction with Lignin Peroxidase from Phanaerochaete Chrysosporium and Bacterial Peroxidase from Pseudomonas Putida - maximising the efficiency of our ARC.
A bioprocess employing the ARC in an industrial setting has been developed and various modes of operation explored. This may serve as an end-of-pipe, lucrative addition to facilities expelling azo dye contaminants. Furthermore, xenobiological approaches to biosafety are considered and a proposal for an “azotrophic” organism paves the way for a new era in synthetic biology biosafety.
For our iGEM project we developed a process to controllably degrade and detoxify the excess azo dye effluent at the source - the textile factories - before they even reach the water systems. We achieved this goal by introducing the genes for three enzymes related to the degradation of these dyes: azoreductase, laccase, and lignin peroxidase into a host E.coli cell to create an enhanced azo dye decolourising organism.
We also designed an integrated end-of-pipe method for detoxifying dye factory wastewater effluent streams by incorporating our engineered E. coli strain in a two-stage process to ensure optimal conditions for the degradation of azo dyes within a batch bioreactor system. The potential for scalability of this method would present various economic and environmental advantages for industries that generate large amounts of dyestuff. The system we have developed could also be enhanced to become a modular bioprocess method for wastewater treatment of other toxic, normally recalcitrant chemicals.
This year, UCL has a highly interdisciplinary team of undergraduates and postgraduates, forming a synbio community at UCL. We are all genuinely delighted to be trying to bring synthetic biology to the world around us. This year we have accomplished immense public engagement and tackled key issues regarding policy and practices.
