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| + | <h1>Local Laws</h1> |
| − | <h1>Crowdfunding</h1> | + | <hr class= "line"> |
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| + | <p> So far China has legislated to control the usage of genetically modified organisms (GMOs) in agriculture and food industries. More specifically, according to our investigation, the GMOs laws regulating the environmental effects of planting genetically modified soybean, oilseed rape, and corn are emphasized. However, China has not yet legislated against industrial application of GMOs. What our team research into was " Agricultural Genetically Modified Organisms Control Ordinance " of Chinese Order No. 304 of the State Council. Under the new, stricter GMOs rules, both foreign suppliers and local importers must apply for GMOs safety certificates and labeling certificates from China's Ministry of Agriculture.</p> |
| − | <p> Soil contamination due to crude oil causes environmental and health-related problems. Our project engineers <i>Bacillus subtilis</i> that function as surfactin producing units to remediate contaminated soils. Surfactin is a biosurfactant that can emulsify hydrophobic organic compounds and, in turn, enhance the biodegradation process. To synthesize and export surfactin more efficiently, we overexpress sfp, the 4’-phosphopantetheinyl-transferase, and YerP, a surfactin efflux pump. In addition, lmrA, a multidrug resistance transporter from <i>Lactococcus lactis</i>, is mutated and tested for higher surfactin specificity. We want our product to provide a greener and safer alternative to methods such as heat treatment and leaching. Biosurfactants and the introduction of <i>Bacillus subtilis</i> should have fewer impacts on soil microbiome, and should be more effective than relying on bioremediation alone. We hope that our project can contribute to the use of <i>B. subtilis</i> as a chassis in synthetic biology, and explore new methods of utilizing multi-drug resistance factors.<p> | + | <p> To take strict precautions against damaging environment and our health, we analyzed two acts that are related to our experiment. The third act defined GMOs as genetically processed plants, animals, microbes, and their products, including:</p> |
| − | <p></p>
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| − | <h1>Introduction</h1>
| + | <li>1. Genetically modified animals, plants (seeds, breeding livestock, aquatic fingerlings), and microbes.</li> |
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| + | <li> 2. Genetically modified animals, plants, and microbe products.</li> |
| − | <p>Oil contamination is a very severe type of environmental degradation. It is estimated that 20-30% of oilfields in China are already contaminated, with a total area that exceeds 48000 km2. The major culprit for such a hazardous problem in oilfields is usually credited to unprocessed solid wastes that contain oily sludge, which has been left to stagnate for years and amounts to over three million tons in total mass.</p>
| + | <li>3. Directly processed GMOs.</li> |
| − | <p></p>
| + | <li>4. Seeds, living stocks, aquatic fingerlings, pesticides, veterinary medicine, fertilizers, and chemical additives containing genetically modified ingredients. </li> |
| − | <p>Leaking oil adheres to plant roots after its entry into the soil and causes root systems to rot, which drastically decreases crop yield in fields nearby. With excessive oil accumulating in the soil, even crops grown in the land become malodorous and unsafe to eat.</p>
| + | </ol> |
| − | <p></p>
| + | <p> Moreover, the thirteenth act is especially crucial to our experiment since it is about safety requirement when experimenting. The GMOs experiment should be undertaken in three processes: intermediate test, environmental release, and production test. First, the intermediate test is the small- scaled experiment which can be controlled and monitored by testers. Second, the environmental release is the middle- scaled experiment under natural conditions with safety precautions. Last, the production test is the large- scaled experiment before actually producing and exercising GMOs.</p> |
| − | <p>Various aromatic compounds in oil, like benzene and naphthalene, and aliphatic hydrocarbons are now clearly known to be carcinogenic, pathogenic and teratogenic even at concentrations as low as few ppm. When healthy soil, a natural breed ground for countless microscopic organisms and supplier of water and mineral for plants becomes contaminated by oils, toxic substances flow along the food chain and amplify in concentration through biomagnification. They finally enter human bodies and accumulate in adipose tissues to a life-threatening amount in the long run. Therefore, we feel urgent to deal with oil contamination for the sake of the health of our dear citizens.</p>
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| − | <p>One crucial step for solving the problem relies upon the remediation of damaged soil. While traditionally the issue is approached from a physical or chemical perspective, for example, by the mean of incineration and chemical leaching, both of which are deteriorative to the environment due to their potential of augmenting the greenhouse effect, polluting the air with sulfurous gases or leaving behind organic solvents in the soil, we are willing to face it biologically and adopt an eco-friendly solution.</p>
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| − | <p></p>
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| − | <p>Cleaning up oil leaks with bioremediation is becoming mature nowadays. By utilizing the metabolic power of microorganisms, not only toxic substances in soil and water bodies nearby can be decomposed to water and other harmless compounds, the overall integrity of soil ecosystem is also preserved to the most extent. Among all agents employed in the process of bioremediation, surfactants play a key role by emulsifying insoluble oil layers into tiny droplets that can be efficiently degraded by soil microbes.</p>
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| − | <p></p>
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| − | <p>It’s now well known that Bacillus subtilis, a well characterized gram-positive bacteria that is extensively used in protein production, and its related strains are able to produce surfactin, a biosurfactant that is originally used by the bacteria to reduce the surface tension of the substrate to achieve swarming behavior. As a replacement for chemically synthesized surfactants, surfactin has several advantages:</p>
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| − | <li>It has lower toxicity and it’s totally biodegradable. Therefore it’s safe and eco-friendly in this application. A previous study on mice shows that it has no impact on several physiological functions when the dosage is below 47.5mg/kg.</li>
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| − | <li>It’s effective even under extreme temperatures, pH conditions, and salinity levels. Elaborate??!!!</li>
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| − | <li>It efficiently facilitates the biodegradation of various carbohydrates: an 88-day long field study suggests that surfactin-enhanced soil has carbohydrate concentration decreased from 6981mg/kg to 1655mg/kg while the control group…??!!</li>
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| − | </ol>
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| − | <p></p>
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| − | <p>We believe that surfactin will be useful for emulsifying leaked oil, thus, it can greatly facilitate the bioremediation of oil-contaminated lands.</p>
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| − | <h1>Our Idea</h1>
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| − | <p>We now propose a synthetic biological device called Mobile Surfactant Factory to help clean up oil contamination more efficiently through bioremediation. That is, we wish to design a new microorganism that is able to produce surfactin in bulk and digest oil carbohydrates as well.</p>
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| − | <p></p>
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| − | <p> According to the goal, we choose Bacillus subtilis as our chassis and determined the biological parts we need to use to implement our ideas. The reason that we choose Bacillus subtilis is obvious: it’s a model organism for studying many biological processes; some strains are already known to be surfactin producers and the genetic components are well characterized. Another consideration is critical to our design yet less obvious: transporters capable of mediating surfactin efflux are scattered among Bacillus subtilis strains and other Gram- positive bacteria so we can further augment surfactin production by excreting it quickly using them. </p> | + | |
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| − | <h1>Discovering LmrA</h1>
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| − | <p>Multidrug resistance exhibited by pathogenic microorganisms and human cancer cells drastically reduces the effectiveness of clinically used drugs and threatens the quality of our lives. One major mechanism causing multidrug resistance has to do with xenobiotic efflux transporters on cell membranes that actively pumps out a plethora of toxic substances out of the cell. During the investigation on surfactin’s properties, we learned that besides being an outstanding biosurfactant, it’s also a wide-spectrum cyclopeptide antibiotic. Using a reverse logic, we decide that we can try to excrete surfactin with transporters that lead to multidrug resistance. Based on previous studies, we choose a well-characterized MDR transporter called lmrA, which origins from Lactococcus lactis(also a G+ bacteria) for our purpose because it’s sequence, structure, function and substrate diversity is already elucidated and it’s confirmed that lmrA confers resistance to 17 out of 21 clinically most used antibiotics and other drugs that belong to the classical MDR spectrum.(consider revising the final part!!!)</p>
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| − | <p></p>
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| − | <h1>sfp – The Master Regulator in Surfactin Biosynthesis</h1>
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| − | <p>I need something here</p>
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| − | <h1>Yerp - The Endogenous Surfactin Exporter</h1>
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| − | <p>I need something here</p>
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| − | <p></p>
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| − | <h1>References</h1>
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| | </div> | | </div> |
| | </section> | | </section> |
