Difference between revisions of "Team:NCKU Tainan/Improvement"

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                                         <a href="https://static.igem.org/mediawiki/2021/0/0b/T--NCKU_Tainan--improvement2.png" target="_blank" style="width:50%"><img src="https://static.igem.org/mediawiki/2021/0/0b/T--NCKU_Tainan--improvement2.png" alt="" title="" style="width:100%"></a>
 
                                         <a href="https://static.igem.org/mediawiki/2021/0/0b/T--NCKU_Tainan--improvement2.png" target="_blank" style="width:50%"><img src="https://static.igem.org/mediawiki/2021/0/0b/T--NCKU_Tainan--improvement2.png" alt="" title="" style="width:100%"></a>
                                        <figcaption>Fig. 4. <i>p</i>-Coumaric acid/OD600 levels of <i>E. coli</i> Nissle with TAL and tyrP in LB with 1mM tyrosine incubated for 48 hours.</figcaption>
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                                      <figcaption>Fig. 3. soxR-P<sub>soxS</sub>-sfGFP</figcaption>
 
                                     </figure>
 
                                     </figure>
 
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                         <p>    We compared the TAL constructs containing the native and B0034 ribosome binding sites, (<a href="http://parts.igem.org/Part:BBa_K2997009" target="_blank">BBa_K2997009</a> and <a href="http://parts.igem.org/Part:BBa_K2997010" target="_blank">BBa_K2997010</a>) to determine if <i>p</i>-Coumaric Acid production is improved by changing the ribosome binding sites. From the results seen in Fig. 4, <a href="http://parts.igem.org/Part:BBa_K2997010" target="_blank">BBa_K2997010</a> is able to produce a higher amount of <i>p</i>-Coumaric acid. Hence, we are able to prove that by changing the RBS (from Native to B0034), the conversion of tyrosine into <i>p</i>-Coumaric acid can increase by 1.73-fold. Therefore, we have shown that we have improved a previous BioBrick.</p>
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                         <p>    In this experiment, an overnight culture was prepared, diluted 10 times and transferred into the 96 well plate. The inducer (paraquat-PQ) was added after incubating in 37 °C.The sfGFP expression level was measured hourly during the 4.5 hours after paraquat induction using an ELISA reader.</p>
                         <p>    For more information, please visit our <a href="https://2019.igem.org/Team:NCKU_Tainan/Results" target="_blank">Results page.</a></p>
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                        <p>    We compared sfGFP expression levels of soxS promoter with and without the activation of SoxR transcription factor. As shown in Fig. 3., sfGFP expression levels were higher with SoxR than without SoxR. In addition, there was no leakage problem after we added SoxR into our biobrick<sup>[<a href="#ref4">4</a>]</sup>.[Fig. 4]</p>
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                                        <a href="https://static.igem.org/mediawiki/parts/6/63/T--NCKU_Tainan--Low_sfGFP_Expression_%28PsoxS%29.png" target="_blank" style="width:50%"><img src="https://static.igem.org/mediawiki/parts/6/63/T--NCKU_Tainan--Low_sfGFP_Expression_%28PsoxS%29.png" alt="" title="" style="width:100%"></a>
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                                        <a href="https://static.igem.org/mediawiki/parts/3/33/T--NCKU_Tainan--Del_Low_sfGFP_Expression_%28soxR-PsoxS%29.png" target="_blank" style="width:50%"><img src="https://static.igem.org/mediawiki/parts/3/33/T--NCKU_Tainan--Del_Low_sfGFP_Expression_%28soxR-PsoxS%29.png" alt="" title="" style="width:100%"></a>
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                                      <figcaption>Fig. 4. Leakage problem was perfectly solved after the improvement.</figcaption>
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                                    </figure>
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                            </div>
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                         </div>
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                  <p>    Please visit <a href="https://2021.igem.org/Team:NCKU_Tainan/Results">Results page</a> for more information.</p>
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                         <li id="ref1">https://2007.igem.org/wiki/index.php/Edinburgh/Team </li>
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                         <li id="ref1">Overkamp W, Beilharz K, Detert Oude Weme R, et al. Benchmarking Various Green Fluorescent Protein Variants in Bacillus subtilis, Streptococcus pneumoniae, and Lactococcus lactis for Live Cell Imaging. <i>Applied and Environmental Microbiology</i>. 2013;79(20):6481-6490. doi:10.1128/aem.02033-13</li>
                         <li id="ref2">Chen, H., Bjerknes, M., Kumar, R., & Jay, E. (1994). Determination of the optimal aligned spacing between the Shine – Dalgarno sequence and the translation initiation codon of <i>Escherichia coli</i>  mRNAs. <i>Nucleic Acids Research, 22</i>(23), 4953–4957. </li>
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                      <li id="ref2"><i>Creation, Expression, Purification and Characterization of GFP G4b GFP Expression and Melting Curves.<a href="https://www.biophysik.physik.uni-muenchen.de/teaching/laboratory_courses/gfp_expression/g4b_gfp_expressionenglish_2017.pdf">https://www.biophysik.physik.uni-muenchen.de/teaching/laboratory_courses/gfp_expression/g4b_gfp_expressionenglish_2017.pdf</a> </i></li>
                        <li id="ref3">https://2013.igem.org/Team:Uppsala</li>
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                         <li id="ref3">Baez A, Shiloach J. Escherichia coli avoids high dissolved oxygen stress by activation of SoxRS and manganese-superoxide dismutase. <i>Microbial Cell Factories</i>. 2013;12(1):23. doi:10.1186/1475-2859-12-23</li>
                    </ol>
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                      <li id="ref4">Seo S, Kim D, Szubin R, Palsson Bernhard O. Genome-wide Reconstruction of OxyR and SoxRS Transcriptional Regulatory Networks under Oxidative Stress in Escherichia coli K-12 MG1655. <i>Cell Reports</i>. 2015;12(8):1289-1299. doi:10.1016/j.celrep.2015.07.043</li>
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                    <li id="ref5">Part:BBa E0040 - parts.igem.org. Igem.org. Published 2013. Accessed October 16, 2021. <a href="http://parts.igem.org/Part:BBa_E0040">http://parts.igem.org/Part:BBa_E0040</a></li>
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Revision as of 15:57, 20 October 2021




Overview

In our project, the superfolder green fluorescent protein (sfGFP) allows better quantification of promoter strength and sensitivity.[1,2]. In the oxidative stress sensing system biobrick, we improved the biobrick BBa_K2610031 from the 2019 iGEM Leiden team by changing GFP (BBa_E0040)[2]. into sfGFP(BBa_I746916), which is hypothesized to have a higher expression level than GFP [Fig. 1]. We also added transcription activator SoxR to our biobrick for increased function of the oxidative stress sensing system[3].

Fig.1. Improvement big picture

Results

Disk assay

Disk assay was used to check the effect of each inducer. The concentration of the different inducers we used are listed below:

Inducer Volume per disk
H2O2s (30%) 10μl
H2O2w (3%) 10μl
MD (menadione)(10mM) 10μl
DMSO (solvent for MD) 10μl
PQ (paraquat)(1mM) 10μl
MQ (solvent for PQ) 10μl
Table 1. Oxidative stress inducers

With sfGFP, the induced system result can be checked under UV light, making it easier to tell the difference between each inducer. [Fig 2.]

Fig. 2. The induced result is clear to be seen after the improvement.

Oxidative Stress Assay

Fig. 3. soxR-PsoxS-sfGFP

In this experiment, an overnight culture was prepared, diluted 10 times and transferred into the 96 well plate. The inducer (paraquat-PQ) was added after incubating in 37 °C.The sfGFP expression level was measured hourly during the 4.5 hours after paraquat induction using an ELISA reader.

We compared sfGFP expression levels of soxS promoter with and without the activation of SoxR transcription factor. As shown in Fig. 3., sfGFP expression levels were higher with SoxR than without SoxR. In addition, there was no leakage problem after we added SoxR into our biobrick[4].[Fig. 4]

Fig. 4. Leakage problem was perfectly solved after the improvement.

Please visit Results page for more information.

References

  1. Overkamp W, Beilharz K, Detert Oude Weme R, et al. Benchmarking Various Green Fluorescent Protein Variants in Bacillus subtilis, Streptococcus pneumoniae, and Lactococcus lactis for Live Cell Imaging. Applied and Environmental Microbiology. 2013;79(20):6481-6490. doi:10.1128/aem.02033-13
  2. Creation, Expression, Purification and Characterization of GFP G4b GFP Expression and Melting Curves.https://www.biophysik.physik.uni-muenchen.de/teaching/laboratory_courses/gfp_expression/g4b_gfp_expressionenglish_2017.pdf
  3. Baez A, Shiloach J. Escherichia coli avoids high dissolved oxygen stress by activation of SoxRS and manganese-superoxide dismutase. Microbial Cell Factories. 2013;12(1):23. doi:10.1186/1475-2859-12-23
  4. Seo S, Kim D, Szubin R, Palsson Bernhard O. Genome-wide Reconstruction of OxyR and SoxRS Transcriptional Regulatory Networks under Oxidative Stress in Escherichia coli K-12 MG1655. Cell Reports. 2015;12(8):1289-1299. doi:10.1016/j.celrep.2015.07.043
  5. Part:BBa E0040 - parts.igem.org. Igem.org. Published 2013. Accessed October 16, 2021. http://parts.igem.org/Part:BBa_E0040