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Team:Bielefeld-CeBiTec/Results/CO2-fixation/Measurement
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<h6>Cultivation</h6> | <h6>Cultivation</h6> | ||
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| - | The aim of the cultivation was to characterize the carbon dioxide fixation in <i>E. coli</i> by an appropriate process. For this approach we wanted to establish a fermentation process, where <i>E. coli</i> is growing first under aeration to obtain aerobic growth conditions to determine the carbon dioxide fixation of the RuBisCo and the Carboxysome afterwrds under this condition, as well as conditions were oxygen is limited, but still aeration takes place. Besides we wanted to ensure that an effective carbon dioxide fixation would be measured. Therefore we gased in additional carbon dioxide, resulting in an 10 fold hihger atmospheric concentraction of 0,312 %. Besides there were no experience described in litarature how much carbon dioxide can be used by a hetereotrophic bacteria like <i>E. coli</i>. To determine even the slightest change in the carbon dioxide balance a the very sensitive <a href="http://www.qubitbiology.com/algae-and-bacteria/photosynthesis-respiration-a-b/q-s151-co2-analyzer-0-2000ppm/" target="_blank">Qubit Analyzer</a> was used for the carbon dioxide fixation...<br> | + | The aim of the cultivation was to characterize the carbon dioxide fixation in <i>E. coli</i> by an appropriate process. For this approach we wanted to establish a fermentation process, where <i>E. coli</i> is growing first under aeration to obtain aerobic growth conditions to determine the carbon dioxide fixation of the RuBisCo and the Carboxysome afterwrds under this condition, as well as conditions were oxygen is limited, but still aeration takes place. Besides we wanted to ensure that an effective carbon dioxide fixation would be measured. Therefore we gased in additional carbon dioxide, resulting in an 10 fold hihger atmospheric concentraction of 0,312 %. Besides there were no experience described in litarature how much carbon dioxide can be used by a hetereotrophic bacteria like <i>E. coli</i>. To determine even the slightest change in the carbon dioxide balance a the very sensitive <a href="http://www.qubitbiology.com/algae-and-bacteria/photosynthesis-respiration-a-b/q-s151-co2-analyzer-0-2000ppm/" target="_blank">Qubit Analyzer</a> was used for the carbon dioxide fixation...<br> |
| + | Besides the complex equilibrium of carbon dioxide (CO<sub>2</sub>) and bicarbonate (HCO<sub>3</sub><sup>-</sup> as shwon in Figure 1 have to be considered. One aspect is that the higher concentration of carbon dioxide is inhibiting hte bacterial growth by stressing the cell to maintain the intracelluar pH value and decreasing the pH optimum of its enzymes when the cell is not able to regulate the pH anymore. A higher concentration of carbon dioxide (CO<sub>2</sub>) is archieved by excess pressure, a higher stirrer speed or lower pH value. | ||
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<div class="element" style="width:600px"> | <div class="element" style="width:600px"> | ||
<a href="https://static.igem.org/mediawiki/2014/f/f8/Bielefeld-CeBiTec_2014-10-17_Carbonat_eq.png" target="_blank"><img src="https://static.igem.org/mediawiki/2014/f/f8/Bielefeld-CeBiTec_2014-10-17_Carbonat_eq.png" width="600px" align="center"></a><br> | <a href="https://static.igem.org/mediawiki/2014/f/f8/Bielefeld-CeBiTec_2014-10-17_Carbonat_eq.png" target="_blank"><img src="https://static.igem.org/mediawiki/2014/f/f8/Bielefeld-CeBiTec_2014-10-17_Carbonat_eq.png" width="600px" align="center"></a><br> | ||
| - | <font size="2" style=""><b>Figure x:</b> Carbonate | + | <font size="2" style=""><b>Figure x:</b> Carbonate equilibrium.</font> |
</div> | </div> | ||
</center> | </center> | ||
Revision as of 02:24, 18 October 2014
Module II - Carbon Dioxide (CO2) Fixation
Cultivation
The aim of the cultivation was to characterize the carbon dioxide fixation in E. coli by an appropriate process. For this approach we wanted to establish a fermentation process, where E. coli is growing first under aeration to obtain aerobic growth conditions to determine the carbon dioxide fixation of the RuBisCo and the Carboxysome afterwrds under this condition, as well as conditions were oxygen is limited, but still aeration takes place. Besides we wanted to ensure that an effective carbon dioxide fixation would be measured. Therefore we gased in additional carbon dioxide, resulting in an 10 fold hihger atmospheric concentraction of 0,312 %. Besides there were no experience described in litarature how much carbon dioxide can be used by a hetereotrophic bacteria like E. coli. To determine even the slightest change in the carbon dioxide balance a the very sensitive Qubit Analyzer was used for the carbon dioxide fixation...
Besides the complex equilibrium of carbon dioxide (CO2) and bicarbonate (HCO3- as shwon in Figure 1 have to be considered. One aspect is that the higher concentration of carbon dioxide is inhibiting hte bacterial growth by stressing the cell to maintain the intracelluar pH value and decreasing the pH optimum of its enzymes when the cell is not able to regulate the pH anymore. A higher concentration of carbon dioxide (CO2) is archieved by excess pressure, a higher stirrer speed or lower pH value.
Figure x: Carbonate equilibrium.
Figure x: Carbonate equlibration.
Figure x: Calibration 10%.
Figure x: Calibration 4%.
Figure x: Calibration by linear fit of the output signal of the qubit analyzer to determine the carbon dioxide fixation.
Figure x: Comparision of the calibration by the measured carbon dioxide using the Qubit Analyzer and calculation from the measured flow rates of the system.
Figure x: Cultivation process.
References
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Sage, Rowan F. „Variation in the K(cat) of Rubisco in C(3) and C(4) Plants and Some Implications for Photosynthetic Performance at High and Low Temperature“. Journal of Experimental Botany 53, no. 369 (2002): 609–20.
