Multi-purpose bioreactor for gas fermentations with suspended or immobilized acetogenic microorganisms

Peter Riegler, doctoral thesis Technical University of Munich, 2018


Synthesis gas can be used by acetogenic bacteria for the production of organic acids and alcohols. A new multi-purpose bioreactor was operated as a stirred-tank, gas-lift, packed-bed biofilm or trickle-bed biofilm reactor to investigate the conversion of syngas with Clostridium aceticum and Clostridium carboxidivorans at comparable operating conditions. The investigations enabled the selection of a suitable bioreactor in match with the individual metabolic performance of each microorganism.


  • Riegler P, Bieringer E, Chrusciel T, Stärz M, Löwe H, Weuster Botz D (2019): Continuous conversion of CO2/H2 with Clostridium aceticum in biofilm reactors. Biores Technol 291: 121760.
  • Riegler P, Chrusciel T, Mayer A, Doll K, Weuster Botz D (2019): Reversible retrofitting of a stirred-tank bioreactor for gas-lift operation to perform syngas fermentation studies. Biochem Eng J 141: 89-101.
  • Bengelsdorf FR, Beck MH, Erz C, Hoffmeister S, Karl MH, Riegler P, Wirth S, Poehlein A, Weuster-Botz D, Dürre P (2018): Bacterial anaerobic synthesis gas (syngas) and CO2 + H2 fermentation. Adv Appl Microbiol 103: 143-221.