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Masterarbeit: Making bioplastics from electricity and CO2: Improving PHA electrosynthesis by Kyrpidia spormannii


The microbial electrosynthesis of bioplastics from anthropogenic CO2 and renewable electricity is a promising technology to mitigate the current climate crisis. A potential chassis for this bioconversion is the thermophilic knallgas bacterium Kyrpidia spormannii. It can produce polyhydroxyalkanoate (PHA), a bioplastic, relying on CO2 for carbon and a cathode for energy. Recent work has aimed at optimizing PHA production via modifications to culture conditions1 and cathode material2. Furthering this effort, additional research is necessary on the cultivation strategies, bioreactor configuration and downstream processing. The goal of this project is to carry out tests on all these levels and assess their specific implications for PHA production.


Research questions include:


  1. Can PHA accumulation be induced in K. spormannii via nutrient limitation? If so, what type of nutrient limitation results in the highest yield?
  2. What are the length and monomer composition of K. spormannii’s PHA? Do they change with cultivation conditions?
  3. Can the production of K. spormanni’s biomass be increased with the use of 3D cathodes?  


The general approach for this work will be the cultivation of K. spormanni in H-cells with different media and cathode configurations followed by analysis with qPCR, HPLC, fluorescence microscopy and electrochemical techniques.


Learning goals include:

  1. Planning and execution of a research project;
  2. Cultivation of thermophilic and anaerobic/microaerobic microorganisms;
  3. Set-up and operation of microbial electrochemical systems;
  4. Application and interpretation of the data from the analytics cited above;
  5. Communication of scientific work both in oral and written forms.



September 1st, 2022



Period of time:

6 months


G. Pillot, S. Sunny, V. Comes, A. Heussner, S. Kerzenmacher  Effect of cathode properties on the thermophilic electrosynthesis of PolyHydroxyAlkanoates by Kyrpidia spormannii, Bioresource Technology Reports, Vol. 18, June (2022).

G. Pillot, S. Sunny, V. Comes, S. Kerzenmacher; Optimization of growth and electrosynthesis of PolyHydroxyAlcanoates by the thermophilic bacterium Kyrpidia spormannii, Bioresource Technology Reports, Vol. 17, February (2022).



Dr. Guillaume Pillot (pillotprotect me ?!uni-bremenprotect me ?!.de

M. Sc. Tiago Ramalho (tramalhoprotect me ?!uni-bremenprotect me ?!.de)