Difference between revisions of "Team:HUST-China/Comparison between PSB"

                               <li><a class="waves-effect waves-dark" href="https://2018.igem.org/Team:HUST-China/Comparison between PSB">Comparison between PSB</a></li>

                               <li><a class="waves-effect waves-dark" href="https://2018.igem.org/Team:HUST-China/Collaborations">Human Practices</a></li>

         <h2 class="pageTitle">Comparison_between_PSB</h2>

                   <h3><strong>1. <span class="red-content">Abstract</span></strong></h3>

                   <h3><strong>2. <span class="red-content">Overview</span></strong></h3>

             <h3 style="text-indent: 2em;"><span class="red-content">functions</span></strong></h3>

                                 <p>These functions calculate the growth rate of <i>Synechocystis</i>. The two functions correspond to different concentrations of CO₂ in the solution.<img  style="vertical-align:middle;height:50px" src="https://static.igem.org/mediawiki/2018/3/36/T--HUST-China--2018-model-new-c003.png">and<img  style="vertical-align:middle;height:60px" src="https://static.igem.org/mediawiki/2018/b/bf/T--HUST-China--2018-model-new-c004.png">make the growth rate decline when the concentration of CO₂ in the solution is too high or too low. (David et al. 2015)^[1]. From the same reference we get the relationship between the light intensity and the growth rate. The function<img  style="vertical-align:middle;height:50px" src="https://static.igem.org/mediawiki/2018/d/d8/T--HUST-China--2018-model-new-c005.png">is from another reference(XIONG et al. 2012) ^[2]. The parameter <img  style="vertical-align:middle;height:30px" src="https://static.igem.org/mediawiki/2018/0/0c/T--HUST-China--2018-model-new-c006.png"> the decline of the growth rate caused by gene editing. This parameter is introduced to make the growth model of wild <i>Synechocystis</i> fit to the growth of edited ones in the reference (Henrike et al. 2010)^[3].</p>

                                 <img class="img-responsive" style="height:80px" src="https://static.igem.org/mediawiki/2018/c/c4/T--HUST-China--2018-model-new-c007.png">

                                   <img class="img-responsive" style="height:100px" src="https://static.igem.org/mediawiki/2018/9/92/T--HUST-China--2018-model-new-r001.png">

                              </div>

                           <div  class="col-md-6"> <img class="img-responsive" style="height:60px" src="https://static.igem.org/mediawiki/2018/1/19/T--HUST-China--2018-model-new-r006.png">

                                 <td>4.124×10-6</td>

                                 <td>2.340×10₂</td>

                     <h3><strong>Part3: <span class="red-content">Whole design</span></strong></h3>

                         <p>We have designed a bipolar chamber MFC this year. Proton exchange membrane divided it into anode chamber and cathode chamber. Anode chamber containing S.oneidensis, nutrient substance(LB、lactate ) or other electrical producing microbes were sealed to prevent the entry of external oxygen. Considering safety and oxidation-reduction potential, we put ferric chloride solution in cathode chamber so that S.oneidensis can transfer electrons outside of their membranes by electron transport chain. Then electrons will reduce ferric ion into ferrous through carbon cloth and produce electricity.We recorded open circuit voltage curve and load voltage curve of MFCs in each different systems. Also, we have measured the biomass of each system in order to ensure whether the improved electricity could be attributed to more attached <i>Shewanella</i> cells on the anodes or the higher electroactivity of single cell.[11] </p>

                            <img class="img-responsive" src="https://static.igem.org/mediawiki/2018/8/85/T--HUST-China--2018-description-picture12.png.png">

                              <p class="red-content"><strong>Co-culture</strong></p>

                                <p>Obviously, the ecological relationship between microorganisms is very complex. There is not only the competition between them for the nutrient, but also the regulation of metabolites among them including induction, transgenosis and synergistic metabolism. Besides, it has been found that the co-culture of microorganisms can improve the electric efficiency of Microbial Fuel Cell under certain conditions.  </p>

                                <p>Metabolites exchange is a common relationship in co-culturing. Therefore, we have designed a clear microbial metabolic pathway to achieve the conversion from light to electricity as well as used more potential symbiotic relationships between the flora to help improve the electricity production efficiency of MFC.</p>

                                  <p>By consulting literature, we found two kinds of microorganisms——Cyanobacteria and <i>Rhodopseudomonas palustris</i>, both of which can utilize light energy and provide lactate to S.oneidensis after doing molecular construction.  </p>

                                    <p>In order to provide a basic growth environment, we mix the culture medium of different strains.（Please refer to our protocol section for the composition of the mediums.）</p>

                        <div class="col-md-12">

                                <p>Lactate produced by <i>Synechocystis</i> PCC6803 can be used as the optimal carbon source for <i>Shewanella</i>. At the same time, acetate produced by <i>Shewanella</i> can be used as the organic carbon source of <i>Synechocystis</i> PCC6803 to increase the lactate production. And the metabolite exchange of <i>Synechocystis</i> PCC6803 and <i>Shewanella</i> is the basis for our photoautotrophic MFC.[12]. </p>

                                  <p class="red-content"><strong><i>Rhodopseudomonas palustris</i></strong></p>

                                    <p>In the preliminary experiment, we found that there may be more potential interactions in the co-culture of <i>Rhodopseudomonas palustris</i> and <i>Shewanella</i>, which can greatly improve the coulombic efficiency of our MFC (please refer our results section for more detials). This is an unexpected surprise for us, which improve to our confidence in the success of the project.</p>

                            </div>    

                <p style="font-size:12px;">[1]Henrike Niederholtmeyer, Bernd T. Wolfstädter, David F. Savage, Pamela A. Silver, Jeffrey C. Way. Engineering Cyanobacteria to Synthesize and Export Hydrophilic Products. Applied and Environmental Microbiology. 2010, 76(11): 3462-3466.</p>

                <p style="font-size:12px;"><span>[2] 《沼泽红假单胞菌的研究进展及其应用》王跃先、刘德海</span></p>

                <p style="font-size:12px;"><span>[3] 周茂洪 赵肖为 吴雪昌《光合细菌沼泽红假单胞菌同化磷能力的研究》 《科技通报》2002年 第2期 142-146页</span></p>

                <p style="font-size:12px;"><span>[4] KEGG, https://www.genome.jp/kegg/pathway.html</span></p>

                <p style="font-size:12px; "><span>[5] Cloning and sequence analysis of the gene encoding Lactococcus lactis malolactic enzyme: relationships with malic enzymes FEMS Microbiol Lett. 1994 Feb 1;116(1):79-86 </span></p>

                <p style="font-size:12px; "><span>[6] Fine tuning the transcription of ldhA for d-lactate production August 2012, Volume 39, Issue 8, pp 1209–1217 </span></p>

                <p style="font-size:12px; "><span>[7] Transport of L-Lactate, D-Lactate, and Glycolate by the LldP and GlcA Membrane Carriers of Escherichia coli Volume 290, Issue 2, 18 January 2002, Pages 824-829 </span></p>

                <p style="font-size:12px; "><span>[8] Enhancement of Hydrogen Production and Carbon Fixation in Purple Nonsulfur Bacterium Bacterium by Synthetic Biology Shou-Chen Lo</span></p>

                <p style="font-size:12px;"><span>[9] Jcat, http://www.jcat.de/#opennewwindow  </span></p>

                <p style="font-size:12px;"><span>[10] Genomic reconstruction of

                <i>Shewanella</i> oneidensis MR-1 metabolism reveals a previously uncharacterized machinery for lactate utilization PNAS February 24, 2009 106 (8) 2874-2879  </span></p>

                <p style="font-size:12px;"><span>[11] Modular Engineering Intracellular NADH Regeneration Boosts Extracellular Electron Transfer of <i>Shewanella</i> oneidensis MR‑1  ACS Synth. Biol. 2018, 7, 885−895</span></p>

                <p style="font-size:12px;"><span>[12]Varman A. M., Yu Y., You L. & Tang Y. J. Photoautotrophic production of d-lactate in an engineered cyanobacterium. Microb. Cell Fact. 12, 117 (2013). </span></p>