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| − | <h2>Project Description</h2>
| + | <br> |
| − | <h4>The Looming Energy Crisis</h4> | + | <h2>Project Overview</h2> |
| − | <p>The global population currently faces a looming energy crisis<sup>1,2</sup>. | + | |
| − | Fossil fuels - the traditional sources of energy used to facilitate human civilisation - are dwindling in supply<sup>1</sup>.
| + | |
| − | Therefore, alternative energy sources must be discovered and developed in order to achieve future energy security.</p>
| + | |
| | | | |
| − | <h4>Attempted Solutions</h4>
| + | <p>There are three main components in our project this year:</p> |
| − | <p>Renewable energy technologies which indirectly harness the power of the sun - such as wind and wave power - are currently utilised across the world in varying degrees<sup>2,3</sup>. | + | <ul> |
| − | It is also increasingly popular to directly harness solar power by converting light energy to electrical energy in solar cells<sup>3</sup>.
| + | <li><b>Chlorophyll Biosynthesis Pathway</b></li> |
| − | However, there are issues associated with the implementation of this technology such as the energy-expensive nature of solar cell and battery construction and maintenance.</p>
| + | <ul> |
| | + | <li>By expressing 4 operons the protoporphyrin-IX molecule can be transformed into chlorophyll-<i>a</i>.</li> |
| | + | <li>Protoporphyrin-IX is present within <i>E. coli</i> and is typically used to make a different tetrapyrrole: heme.</li> |
| | + | </ul> |
| | + | <li><b>Photosystem II</b></li> |
| | + | <ul> |
| | + | <li>Through the expression of 5 operons we aim to induce <i>E. coli</i> to build the Photosystem II protein complex which contains the Oxygen Evolving Centre of photosynthesis.</li> |
| | + | </ul> |
| | + | <li><b>Hydrogenase</b></li> |
| | + | <ul> |
| | + | <li>A hydrogenase enzyme can take two protons and two electrons to build H<sub>2</sub> (molecular hydrogen).</li> |
| | + | </ul> |
| | + | </ul> |
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| − | <h4>Photosynthesis - Nature’s Answer to the Problem</h4>
| + | <br> |
| − | <p>It's well known that photosynthesis is nature's own way of converting light energy from the sun into chemical energy in the form of glucose. | + | |
| − | The goal of Macquarie University's 2015 iGEM team - the Solar Synthesisers - is to utilise the solar-harnessing powers of chlorophyll and photosystem II in order to produce an environmentally friendly and renewable source of chemical energy, namely hydrogen gas.
| + | |
| − | When combusted hydrogen gas produces only water and energy - this is highly desirable from an environmental perspective<sup>4</sup>.</p>
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| | | | |
| − | <h4>The Solar Synthesisers’ Project</h4> | + | <div class="centreStuffInline"> |
| − | <p>To achieve this goal we're building on the work of last year's Macquarie University iGEM team by transforming <i>E. coli</i> with the genes required to complete the <a class="regularHyperlink" href="https://2015.igem.org/Team:Macquarie_Australia/Notebook1CBP">chlorophyll biosynthesis pathway</a> and create <a class="regularHyperlink" href="https://2015.igem.org/Team:Macquarie_Australia/Notebook2PSB">photosystem II</a> in this bacterial species.
| + | <figure class="specialInline"><img src="https://static.igem.org/mediawiki/2015/9/98/MqAust_ProjectDesign_CBP.png" width="860px" alt="Chlorophyll Biosynthesis Pathway diagram"></figure> |
| − | These systems will allow for the use of solar energy to split water into positively-charged hydrogen ions, electrons, and oxygen. | + | </div> |
| − | Our next goal is then to combine the hydrogen ions and electrons produced in this hydrolytic process in a hydrogenase enzyme complex in order to produce <a class="regularHyperlink" href="https://2015.igem.org/Team:Macquarie_Australia/Practices/Implementation">hydrogen gas on an industrial scale</a>. | + | <br> |
| − | Hence in order to produce a renewable and environmentally-friendly source of energy we present the Solar Synthesisers’ 3 step plan: <b>Capture</b>, <b>Transfer</b> and <b>Synthesise</b>!</p> | + | <div class="centreStuffInline"> |
| | + | <figure class="specialInline"><img src="https://static.igem.org/mediawiki/2015/1/14/MqAust_ProjectDesign_PSB.png" width="860px" alt="Photosystem II diagram"></figure> |
| | + | </div> |
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| − | <div class="centreStuffInline"> | + | <div class="centreStuffInline"> |
| − | <figure><img src="https://static.igem.org/mediawiki/2015/8/80/MqAust_ProjectDescAllDiagrams.png" width="880px" alt="Project Overview diagram"></figure> | + | <figure class="specialInline"><img src="https://static.igem.org/mediawiki/2015/ 5/ 58/ MqAust_ProjectDesign_HydA.png" width=" 860px" alt=" Hydrogenase diagram"></figure> |
| | </div> | | </div> |
| − |
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| − | <h5>Capture</h5>
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| − | <p>In order to capture light energy from the sun we aim to use chlorophyll pigment to capture photons.
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| − | We aim to transform and express within <i>E. coli</i> the 13 genes required to complete the chlorophyll synthesis pathway in this species.</p>
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| − |
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| − | <h5>Transfer</h5>
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| − | <p>In photosystem II the energy captured by the chlorophylls is used to split water into protons, electrons, and molecular oxygen.</p>
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| − |
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| − | <h5>Synthesise</h5>
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| − | <p>The next step is the combination of two protons and two electrons in a hydrogenase enzyme complex to synthesise hydrogen gas.
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| − | The commercially-viable production of industrial quantities of hydrogen gas will represent the successful completion of our project.</p>
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| − |
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| − | <h4>What is new from last year?</h4>
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| − | <p>First, we are all new to iGEM!! The full team was only assembled at the end of July 2015, as a capstone class for our Biomolecular sciences major (link to team page and Louise's article in PDF format).
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| − | We completed the genes within the Chlorophyll biosynthesis pathway. (link to results)
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| − | We started, and constructed 14 out of the 17 Photosystem-II genes into biobricks (link to PSII result).
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| − | We modelled the conversion of ALA to PPIX in <i>E. coli</i>, and the production of hydrogen gas using PSII (link to modelling)</p>
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| − |
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| − | <h4>Experimental Organism - Why <i>E. coli</i>?</h4>
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| − | <p>Rather than engineering a naturally-photosynthetic organism and individually targeting genes in a pathway, we chose <i>E. coli</i> as our experimental host so we could engineer an entire novel metabolic pathway of our own design.
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| − | Using <i>E. coli</i> as our host allowed us to incorporate the somewhat large and complex chlorophyll-a biosynthesis pathway, comprising 13 genes, as well as all 17 genes comprising PSII. Incorporation of both pathways in the robust and fast-growing <i>E. coli</i> host provides us with a valuable tool with ‘plug-and-play’ capabilities that allow for further future downstream potentials such as re-engineering the pathway to produce other members of the chlorophyll family.
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| − | </p>
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| − |
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| − | <h4>References</h4>
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| − | <ol>
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| − | <li>Armaroli, N. & Balzani, V. (2011). The hydrogen issue. <i>ChemSusChem</i>, 4, 21–36.</li>
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| − | <li>Kessel, D.G. (2000). Global warming: facts, assessment, countermeasures. <i>Journal of Petroleum Science and Engineering</i>, 26, 157–168.</li>
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| − | <li>Ellabban, O., Abu-Rub, H. & Blaabjerg, F. (2014). Renewable energy resources: current status, future prospects and their enabling technology. <i>Renewable and Sustainable Energy Reviews</i>, 39, 748–764. doi:10.1016/j.rser.2014.07.113.</li>
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| − | <li>Altork, L.N. & Busby, J. R. (2010). Hydrogen fuel cells: part of the solution. <i>Technology and Engineering Teacher</i>, 70(2), 22-27.</li>
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| − | </ol>
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Project Overview
There are three main components in our project this year:
- Chlorophyll Biosynthesis Pathway
- By expressing 4 operons the protoporphyrin-IX molecule can be transformed into chlorophyll-a.
- Protoporphyrin-IX is present within E. coli and is typically used to make a different tetrapyrrole: heme.
- Photosystem II
- Through the expression of 5 operons we aim to induce E. coli to build the Photosystem II protein complex which contains the Oxygen Evolving Centre of photosynthesis.
- Hydrogenase
- A hydrogenase enzyme can take two protons and two electrons to build H2 (molecular hydrogen).
