Molecular hydrogen conversion in phototrophs and heterotrophs with engineered oxygen-tolerant hydrogenases

• Applicants: Professor Dr. Bruno Bühler; Professor Dr. Lars Lauterbach
• Subject Area: Microbial Ecology and Applied Microbiology ; Biochemistry
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 550624628

Molecular hydrogen will be an energy carrier/chemical of the future. Its production, storage, and utilization however face some challenges. Microbial biotechnology approaches offer the potential to efficiently produce H2 as well as to utilize it to drive target reactions. Production via photosynthetic water oxidation can be considered an ideal way to access H2 in an eco-friendly and cost-efficient way. Its utilization by heterotrophic and cyanobacterial cells has the potential to enable novel approaches for eco-efficient redox-bioprocessing. This project aims to investigate and engineer an O2-tolerant hydrogenase for its application under aerobic conditions in heterotrophic and phototrophic hosts. The cofactor dependency of the hydrogenase will be engineered in order to enable light-driven H2 production in cyanobacteria and/or H2-driven oxygenase and reductase catalysis in vivo. Being applied in bacterial host cells, operational hydrogenase variants and productive enzymes interact with cellular metabolism. Such interactions will be investigated with the aim to bring cellular metabolism and target reactions in line and thus engineer efficient and stable whole-cell biocatalysts. This also involves the investigation of electron routes and reaction engineering. In order to achieve the stated goals, the cooperation of experts in hydrogenase biochemistry/molecular biology, microbial physiology, photosynthesis, and biotechnology is essential. The results are expected to pave ways to a sustainable bioeconomy in multiple ways and provide new insights into bacterial physiology and photosynthesis.

• DFG Programme: Research Grants