Establishing Biofilm Models as Tool to study and optimize the Production of Medium Chain Fatty Acids and Alcohols in Membrane Biofilm Reactors

• Applicant: Professorin Dr. Susanne Lackner
• Subject Area: Biological Process Engineering
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 559573880

The aim of this project is to develop mathematical models that can be used for the optimization and upscaling of membrane biofilm reactors. The system to be established is a two-species biofilm for anaerobic syngas fermentation. The two bacteria, Clostridium autoethanogenum and Clostridium kluyveri, will be used for this purpose. C. autoethanogenum can produce acetate with ethanol as a by-product from CO (acetogenesis). Ethanol, butanol and hexanol are produced indirectly on the basis of the corresponding organic acids (acetate, butyrate and caproate, respectively) during solventogenesis. C. kluyveri uses ethanol und acetate as substrates to produce the intermediates butyrate and caproate.The core of the project is the development of 1D and 2D biofilm models which will be used to investigate the establishment of this biofilm system and the optimization of the product yield. For this purpose, the models are iteratively calibrated with specific laboratory tests and validated as far as possible. The biokinetic relationships are investigated in a 1D biofilm model, which is then also used to optimize the operating strategy for the membrane biofilm reactor. The 2D models are used for studies aiming at upscaling and the development of suitable membrane module configurations. To do so, mass transport processes are coupled with different module geometries, flow velocities and biofilm growth. In addition, specific experiments are carried out in order to mathematically describe biofilm detachment and to set an optimum biofilm thickness.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2494: Productive Biofilm Systems
• International Connection: Saudi Arabia
• Cooperation Partner: Professor Dr. Cristian Picioreanu