Difference between revisions of "Team:ICT-Mumbai/Description"

 
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        <a href="https://2017.igem.org/Team:ICT-Mumbai/Background" class="w3-bar-item w3-button">Background</a>
  
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        <a href="https://2017.igem.org/Team:ICT-Mumbai/Description" class="w3-bar-item w3-button">Description</a>
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        <a href="https://2017.igem.org/Team:ICT-Mumbai/Team"class="w3-bar-item w3-button">Team</a>
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Safety</a>
  
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Human Practices</a>
  
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  <h3 class="w3-center" style="color:#000080">The problem</h3>
  
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<p style="height:70 px; font-family:'Lato'; font-size:20px; colour:lightgrey;">Ammonia formed due to hydrolysis of urine is a major cause of the stench that is characteristic of public toilets. Apart from putting off users, ammonia is also a health hazard.
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<blockquote cite="https://www.health.ny.gov/environmental/emergency/chemical_terrorism/ammonia_tech.htm">
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Ammonia is irritating and corrosive. Exposure to high concentrations of ammonia in air causes immediate burning of the nose, throat and respiratory tract. This can cause bronchiolar and alveolar edema, and airway destruction resulting in respiratory distress or failure. Inhalation of lower concentrations can cause coughing, and nose and throat irritation. Ammonia’s odor provides adequate early warning of its presence, but ammonia also causes olfactory fatigue or adaptation, reducing awareness of one's prolonged exposure at low concentrations. <a href="https://www.health.ny.gov/environmental/emergency/chemical_terrorism/ammonia_tech.htm">(Source)</a>
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</blockquote></p>
  
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<p style="height:70 px; font-family:'Lato'; font-size:20px; colour:lightgrey;">Apart from users, toilet janitors are exposed to ammonia for prolonged periods of time. In crowded localities, residents and shopkeepers in the vicinity of public toilets are also exposed to toxic ammonia fumes throughout the day.</p>
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  <h3 class="w3-center" style="color:#000080">Existing Solutions</h3>
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<p style="height:70 px;font-family:'Lato'; font-size:20px; colour:lightgrey;">Different solutions exist to tackle the problem of stinking toilets. The first involves using deodorants, which simply mask the odor. This is obviously not a solution as such, as the toxic fumes are merely disguised and wished away!</p>
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<p style="height:70 px; font-family:'Lato'; font-size:20px; colour:lightgrey;">The second solution is to use an exhaust fan, which sucks away odors to the outside atmosphere. This also is not a solution; the ammonia is simply diluted into the atmosphere.</p>
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<p style="height:70 px; font-family:'Lato'; font-size:20px; colour:lightgrey;">The third solution is using copious amounts of water to clean toilets. While this is the most obvious way to prevent formation of ammonia, it is not the most feasible due to scarcity or even unavailability of water, especially after a poor monsoon. A greater menace is that of unscrupulous persons peeing in public places!</p>
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<p style="height:70 px; font-family:'Lato'; font-size:20px; colour:lightgrey;">The fourth solution is to construct waterless toilets. A version of waterless urinals employs a propriety liquid (usually oil) in the drain. The oil floats on urine, and odors from urine cannot rise from the oil layer. This is not a cheap solution, and also requires periodic flushing with lots of water. <a href="http://science.howstuffworks.com/environmental/green-
#caption {
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tech/sustainable/waterless-toilet4.htm">(Source)</a></p>
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<p style="height:70 px; font-family:'Lato'; font-size:20px; colour:lightgrey;">A fifth solution is to use microbes (Bioblocks®) that degrade the urea in urine, thus preventing ammonia formation. This is by far the neatest solution, as ammonia does not form at all. However, the cost of replacing the microbes in the drainage system is a big impediment to its widespread use.</p>
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</head>
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<p style="height:70 px;  font-family:'Lato';  font-size:20px; colour:lightgrey;">We decided to tackle the problem of stench without reconfiguring existing toilets, which would not be feasible because of the costs involved and the need to convince a number of stakeholders. We also decided that the solution should be agnostic to people’s attitudes and their disdain for cleanliness!</p>
<body>
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<div id="navbar">
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<ul>
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  <li><a href="https://2017.igem.org/Team:ICT-Mumbai">Home</a></li>
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  <li><a class="selected">Description</a></li>
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  <li class="dropdown">
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    <a href="#" class="dropbtn">Knowledge</a>
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    <div class="dropdown-content">
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      <a href="#">Notebook</a>
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      <a href="#">Outreach</a>
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      <a href="#">Team</a>
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    </div>
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  </li>
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</ul>
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<img src="https://static.igem.org/mediawiki/2017/8/8a/T--ICT-Mumbai--ICTLogo.jpeg" height="150" class="logo">
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<h1 class="Head">Project Description</h1>
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<br>
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</div>
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<br>
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<center>
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<div id="toptex">
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<div class="center1">
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<br>
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<center> <h2 style="font-style:italic; text-decoration:underline;">Our Motivation</h1></center>
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<p>
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Public toilets are associated with a foul odour, which is primarily due to ammonia released from decomposition of urine. Not only is ammonia a health hazard, it also deters potential users!
+
Some of the existing solutions to tackle the stench in urinals are:
+
  
 +
<p style="height:70 px;  font-family:'Lato';  font-size:20px; colour:lightgrey;">This, then, is what we propose: the ammonia released in air can be assimilated by bacteria, which will use it as their sole source of nitrogen. The bacteria will metabolize the nitrogen to form a blue-colored compound that can be extracted and used as a dye, thus capturing the ammonia in an inert form.</p>
  
 +
<p style="height:70 px;  font-family:'Lato';  font-size:20px; colour:lightgrey;">We decided to engineer <i>Escherichia coli</i> to carry out the task of ammonia assimilation.
 
</p>
 
</p>
<!-- <ul>
 
    <li><a style="font-weight: bold;">Bio Blocks®:</a> Bio Blocks® are placed in urinals so that they are contacted by urine. These Bio Blocks contain surfactants and frozen microbial spores that break urea into compounds other than ammonia.</li>
 
    <li><a style="font-weight: bold;">Waterless urinals:</a> Waterless toilets exist, but they come at a cost. Also, as plumbing systems are usually not built to run without water, over time, urea in the urine crystallizes and chokes the system.</li>
 
    <li><a style="font-weight: bold;">Air fresheners:</a> Using air fresheners in toilets is a band-aid solution that only masks the stench. Moreover, the fragrance fades after some time ☹</li>
 
</ul> -->
 
  
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  <h5 class="w3-center" style="color:#000080">How it works</h5>
  
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  <p class="pan">Bio Blocks® are placed in urinals so that they are contacted by urine. These Bio Blocks contain surfactants and frozen microbial spores that break urea into compounds other than ammonia.</p>
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<button class="accordion">Waterless urinals</button>
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<div class="panel">
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  <p class="pan">Waterless toilets exist, but they come at a cost. Also, as plumbing systems are usually not built to run without water, over time, urea in the urine crystallizes and chokes the system.</p>
+
</div>
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<button class="accordion">Air fresheners</button>
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<div class="panel">
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  <p class="pan">Using air fresheners in toilets is a band-aid solution that only masks the stench. Moreover, the fragrance fades after some time ☹</p>
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</div>
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+
 
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<p>
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We wish to tackle this situation to make using public toilets less taxing on the senses. Using the tools of synthetic biology, we plan to work toward completely eliminating the odour, instead of merely masking it.
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</p>
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<br>
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</center>
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<br>
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<br>
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<div class="center">
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<center>
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<br>
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<h2 style="font-style:italic; text-decoration:underline;">What we intend to do...</h2>
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<a style="font-style:italic;font-size=5px;"> Click the image below to see the methodology proposed</a>
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</center>
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<img id="myImg" src="https://static.igem.org/mediawiki/2017/1/1a/T--ICT-Mumbai--ProjectDescriptionAnim.gif" alt="Process Description" width="600" height="400">
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<p style="height:70 px;  font-family:'Lato';  font-size:20px; colour:lightgrey;">Ammonia in air dissolves in water to form ammonium, which enters the cell and condenses with glutamate to form glutamine due to the action of the endogenous enzyme glutamine synthetase (GS, encoded by <i>glnA</i>). Glutamine can be acted upon by indigoidine synthetase (encoded by <i>indC</i> from <i>Photorhabdus luminescens</i>) to form the blue pigment indigoidine.</p>
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<p style="height:70 px; font-family:'Lato';  font-size:20px; colour:lightgrey;">Protons released during glutamine formation can be pumped outside the cell by proteorhodopsin (obtained from uncultured marine Gammaproteobacteria of the SAR86 group). The proton gradient thus formed can drive endogenous ATP synthase to form ATP, which is required for GS activity.
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<p style="height:70 px;  font-family:'Lato';  font-size:20px; colour:lightgrey;">A schematic representation of our concept is depicted below:
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We aim to engineer E. coli to assimilate ammonia from the environment, converting it into innocuous byproducts. The engineered microbes will be housed in a compact and portable device that can be installed in public toilets. Air containing ammonia will be channeled through this device, and ammonia will be utilized by the microbes as a source of nitrogen.
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Latest revision as of 15:03, 1 November 2017

ICT-Mumbai 2017

The problem

Ammonia formed due to hydrolysis of urine is a major cause of the stench that is characteristic of public toilets. Apart from putting off users, ammonia is also a health hazard.

Ammonia is irritating and corrosive. Exposure to high concentrations of ammonia in air causes immediate burning of the nose, throat and respiratory tract. This can cause bronchiolar and alveolar edema, and airway destruction resulting in respiratory distress or failure. Inhalation of lower concentrations can cause coughing, and nose and throat irritation. Ammonia’s odor provides adequate early warning of its presence, but ammonia also causes olfactory fatigue or adaptation, reducing awareness of one's prolonged exposure at low concentrations. (Source)

Apart from users, toilet janitors are exposed to ammonia for prolonged periods of time. In crowded localities, residents and shopkeepers in the vicinity of public toilets are also exposed to toxic ammonia fumes throughout the day.

Existing Solutions

Different solutions exist to tackle the problem of stinking toilets. The first involves using deodorants, which simply mask the odor. This is obviously not a solution as such, as the toxic fumes are merely disguised and wished away!

The second solution is to use an exhaust fan, which sucks away odors to the outside atmosphere. This also is not a solution; the ammonia is simply diluted into the atmosphere.

The third solution is using copious amounts of water to clean toilets. While this is the most obvious way to prevent formation of ammonia, it is not the most feasible due to scarcity or even unavailability of water, especially after a poor monsoon. A greater menace is that of unscrupulous persons peeing in public places!

The fourth solution is to construct waterless toilets. A version of waterless urinals employs a propriety liquid (usually oil) in the drain. The oil floats on urine, and odors from urine cannot rise from the oil layer. This is not a cheap solution, and also requires periodic flushing with lots of water. (Source)

A fifth solution is to use microbes (Bioblocks®) that degrade the urea in urine, thus preventing ammonia formation. This is by far the neatest solution, as ammonia does not form at all. However, the cost of replacing the microbes in the drainage system is a big impediment to its widespread use.

Our Solution

We decided to tackle the problem of stench without reconfiguring existing toilets, which would not be feasible because of the costs involved and the need to convince a number of stakeholders. We also decided that the solution should be agnostic to people’s attitudes and their disdain for cleanliness!

This, then, is what we propose: the ammonia released in air can be assimilated by bacteria, which will use it as their sole source of nitrogen. The bacteria will metabolize the nitrogen to form a blue-colored compound that can be extracted and used as a dye, thus capturing the ammonia in an inert form.

We decided to engineer Escherichia coli to carry out the task of ammonia assimilation.

How it works

Ammonia in air dissolves in water to form ammonium, which enters the cell and condenses with glutamate to form glutamine due to the action of the endogenous enzyme glutamine synthetase (GS, encoded by glnA). Glutamine can be acted upon by indigoidine synthetase (encoded by indC from Photorhabdus luminescens) to form the blue pigment indigoidine.

Protons released during glutamine formation can be pumped outside the cell by proteorhodopsin (obtained from uncultured marine Gammaproteobacteria of the SAR86 group). The proton gradient thus formed can drive endogenous ATP synthase to form ATP, which is required for GS activity.

A schematic representation of our concept is depicted below: