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| <img src="https://static.igem.org/mediawiki/2018/3/3d/T--Sorbonne_U_Paris--Chlamydomonas_Ocean.png"alt="Vision of ou project" style="width: 100%"> | | <img src="https://static.igem.org/mediawiki/2018/3/3d/T--Sorbonne_U_Paris--Chlamydomonas_Ocean.png"alt="Vision of ou project" style="width: 100%"> |
| <figcaption style="padding: 10px;"><b>Through our SugaRevolution we want to produce sustainable sugar without harming our | | <figcaption style="padding: 10px;"><b>Through our SugaRevolution we want to produce sustainable sugar without harming our |
− | soil and competing with food crop!</b>We want to engineer a strain of the green microalgae <i>Chlamydomonas reinhardtii</i>,adapted to live in sea water, and able to produce sugar in large amounts. Microalgae‘s photosynthesis uses sunlight and atmospheric CO2 to accumulate sugar in its stored form: starch. By using a photobioreactor for the containment of the algae in the oceans, sugar production would not compete with arable lands. </figcaption> | + | soil and competing with food crop!</b> We want to engineer a strain of the green microalgae <i>Chlamydomonas reinhardtii</i>, adapted to live in sea water, and able to produce sugar in large amounts. Microalgae‘s photosynthesis uses sunlight and atmospheric CO2 to accumulate sugar in its stored form: starch. By using a photobioreactor for the containment of the algae in the oceans, sugar production would not compete with arable lands. </figcaption> |
| </figure> </div> | | </figure> </div> |
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− | <h2 class="title-h2" id="1">Impact of the monocultures on the environment </h2> | + | <h2 class="title-h2" id="1">Impact of Monocultures on the Environment </h2> |
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− | <p> For purposes of clarity, some important impacts that monocultures have on environment are listed hereafter: </p> | + | <p> For purposes of clarity, some important impacts that monocultures have on the environment are listed hereafter: </p> |
| <ul> | | <ul> |
| <li> <b>Soil erosion due to irrigation, wind and harvest</b>[1][3][4]: Where irrigation application is inefficient or rainfall is high, water withdrawal is generally coupled with the loss of valuable soil from the farm. </li> | | <li> <b>Soil erosion due to irrigation, wind and harvest</b>[1][3][4]: Where irrigation application is inefficient or rainfall is high, water withdrawal is generally coupled with the loss of valuable soil from the farm. </li> |
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| <li> <b>Water use</b>[1][6]: Sugar cane ranks among a group of crops noted for their significant water consumption (along with rice and cotton). High water withdrawal is generally coupled with the run-off of polluted irrigation water containing sediment, pesticides and nutrients. </li> | | <li> <b>Water use</b>[1][6]: Sugar cane ranks among a group of crops noted for their significant water consumption (along with rice and cotton). High water withdrawal is generally coupled with the run-off of polluted irrigation water containing sediment, pesticides and nutrients. </li> |
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− | <li><b>Use of chemicals</b>[1]: The use of herbicides in sugar beet cultures is among the highest compared to other crops. Inorganic fertilizers typically supply nitrogen, phosphorus and/or potassium in the mineral form. Environmental impacts generally arise because the nutrients in the fertilizers are not entirely taken up by the crop but move into the environment. The overuse of fertilizers on cane or beet crops is typical of farming in general. </li> | + | <li><b>Use of chemicals</b>[1]: The use of herbicides in sugar beet cultures is among the highest as compared to other crops. Inorganic fertilizers typically supply nitrogen, phosphorus and/or potassium in the mineral form. Environmental impacts generally arise because the nutrients in the fertilizers are not entirely taken up by the crop but move into the environment. The overuse of fertilizers on cane or beet crops is typical of farming in general. </li> |
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| <li><b>Discharge of mill effluents</b>[1]: In some countries with weak environmental laws, a tremendous amount of matter is released straight into the streams. Cane mill effluents tend to include heavy metals, oil, grease and cleaning agents. </li> | | <li><b>Discharge of mill effluents</b>[1]: In some countries with weak environmental laws, a tremendous amount of matter is released straight into the streams. Cane mill effluents tend to include heavy metals, oil, grease and cleaning agents. </li> |
| </ul> <br> <br> | | </ul> <br> <br> |
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− | <p style="background:#E6E6E6; border-radius:10px; font-size:18px"> A sugar factory that mills 1,250 tonnes of sugarcane daily uses 151,000 liters of water per hour and releases 30,000 to 75,000 liters of liquid, solid and gaseous waste. </p> <br><br> | + | <p style="background:#E6E6E6; border-radius:10px; font-size:18px"> A sugar factory that mills 1,250 tons of sugarcane daily uses 151,000 liters of water per hour and releases 30,000 to 75,000 liters of liquid, solid and gaseous waste. </p> <br><br> |
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− | <h2 class="title-h2" id="2">Production of sugar in marine environments by our green microalgae, <i>Chlamydomonas reinhardtii </i></h2> | + | <h2 class="title-h2" id="2">Production of Sugar in marine environments by our modified <i>Chlamydomonas reinhardtii </i></h2> |
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| <p>As a photoautotrophic organism, <i>Chlamydomonas reinhardtii</i> has the ability to fix carbon through carbon dioxide uptake and a source of light. Its metabolism can also be autotrophic, heterotrophic or mixotrophic. All of these characteristics explain why it is an interesting chassis in comparison to other classical model (bacteria or yeasts) which always need an input of energy such as glucose. This microalgae is well-known as a model organism in the research field on photosynthesis and its genome has been characterized[7]. Moreover, growing range of tools in molecular biology have been developed for use in Chlamydomonas, for example a brand new modular cloning tool was created and published in 2018, the MoClo toolkit set by Pierre Crozet et al. This tool offers a new field of possibilities for the use of Chlamydomonas as it is a very interesting microorganism whose biosynthesis and metabolic pathways can be exploited in synthetic biology. Indeed it was established that this microalgae could be used in the future to produce high value compounds for biotechnology industries[8]. </p> | | <p>As a photoautotrophic organism, <i>Chlamydomonas reinhardtii</i> has the ability to fix carbon through carbon dioxide uptake and a source of light. Its metabolism can also be autotrophic, heterotrophic or mixotrophic. All of these characteristics explain why it is an interesting chassis in comparison to other classical model (bacteria or yeasts) which always need an input of energy such as glucose. This microalgae is well-known as a model organism in the research field on photosynthesis and its genome has been characterized[7]. Moreover, growing range of tools in molecular biology have been developed for use in Chlamydomonas, for example a brand new modular cloning tool was created and published in 2018, the MoClo toolkit set by Pierre Crozet et al. This tool offers a new field of possibilities for the use of Chlamydomonas as it is a very interesting microorganism whose biosynthesis and metabolic pathways can be exploited in synthetic biology. Indeed it was established that this microalgae could be used in the future to produce high value compounds for biotechnology industries[8]. </p> |
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− | <h4>How to make this algae survive in marine environment? </h4> | + | <h4>How to make this algae survive in marine environments? </h4> |
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− | <p>Furthermore, to make use of the marine environment to produce sugar, we needed to have a microalgae that can survive in salty water. So we contacted Josianne Lachapelle who worked with <i>Chlamydomonas reinhardtii </i> and adapted some strains to live in high salt concentration medium[9]. And she kindly accepted to provide us with some of these strains that we could use them to make sugar without competing with arable land. </p> | + | <p>To make use of the marine environment during the sugar production, we needed to have a microalgae that can survive in salty water. So we contacted Josianne Lachapelle who worked with <i>Chlamydomonas reinhardtii </i> and adapted some strains to live in high salt concentration medium[9]. And she kindly accepted to provide us with some of these strains that we could use them to make sugar without competing with arable land. </p> |
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| <h4>Which relevant sugar to produce in this algae? </h4> | | <h4>Which relevant sugar to produce in this algae? </h4> |
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− | <p>The sugar we chose to produce in this microalgae is the trehalose C12H22O11. It is a disaccharide of glucose, that can be metabolized by <i>Escherichia coli</i> and <i>Saccharomyces cerevisiae</i>. While, it is also present in <i>Chlamydomonas</i>, however, it is mainly involved in stress response to H<sub>2</sub>0<sub>2</sub> as an antioxidant and not as a source of energy. Without a self-production consumption, Chlamydomonas and trehalose are becoming an interesting combination for energy production. As a result, this source of energy would potentially be fully extracted and used by chassis such as <i>E. coli</i> or <i>S. cerevisiae</i> for the production of molecules of interest by synthetic biology. </p> | + | <p>The sugar we chose to produce in this microalgae is the trehalose C12H22O11. It is a disaccharide of glucose, that can be metabolized by <i>Escherichia coli</i> and <i>Saccharomyces cerevisiae</i>. While it is also present in <i>Chlamydomonas</i>, it is, however, mainly involved in stress response to H<sub>2</sub>0<sub>2</sub> as an antioxidant and not as a source of energy. Without a self-production consumption, Chlamydomonas and trehalose are becoming an interesting combination for energy production. As a result, this source of energy would potentially be fully extracted and used by chassis such as <i>E. coli</i> or <i>S. cerevisiae</i> for the production of molecules of interest by synthetic biology. </p> |
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− | <p>Our discussions with professionals and scientists who work with <i>Chlamydomonas</i> or other microalgae, on directed evolution or on regulation played a major role in the further perspective of our project. </p><br><br> | + | <p>Our discussions with professionals and scientists who work with <i>Chlamydomonas</i> or other microalgae, on directed evolution or on regulations played a major role in the further perspective of our project. </p><br><br> |
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| <p style="background:#E6E6E6; border-radius:10px; font-size:18px">One main conclusion we got from our meetings was that algae did not bring an added value for the production of sugar or biofuels because of its high production costs. Indeed, the cost of production will highly increase because of the energy to bring to the photobioreactor, the extraction and the collection of sugar. </p> <br><br> | | <p style="background:#E6E6E6; border-radius:10px; font-size:18px">One main conclusion we got from our meetings was that algae did not bring an added value for the production of sugar or biofuels because of its high production costs. Indeed, the cost of production will highly increase because of the energy to bring to the photobioreactor, the extraction and the collection of sugar. </p> <br><br> |
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− | <p>Thus, the amount of sugar expected by the use of marine surfaces could not be sufficient to meet the needs of synthetic biology development but would not enable a profitable production </p> | + | <p>Thus, the amount of sugar expected by the use of marine surfaces could be sufficient to meet the needs of synthetic biology development but would not enable a profitable production </p> |
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| <h4>Yield improvement </h4> | | <h4>Yield improvement </h4> |