Concerns about exhaustion of fossil fuels and global warming have led to increasing attention to clean and renewable energy. Here, biohydrogen is a very attractive alternative. The most efficient biohydrogen producers are hydrogenases. These enzymes display fascinating redox-chemical properties with tremendous promise as a biocatalyst for hydrogen fuel. However, due to the complex structure and maturation process of hydrogenases, their heterologous production has been a challenging task and their sensitivity to O2, CO, etc has seriously limited the potential applications.
Within this project we focus on two oxygen-tolerant [NiFe] hydrogenases from the β‑proteobacterium Ralstonia eutropha, the regulatory hydrogenase (RH) and the soluble hydrogenase (SH).
Since the RH is the simplest [NiFe] hydrogenase we use this enzyme as a model for the development of a general strategy for the development of a bioprocess for heterologous hydrogenase production in E. coli. We aim at the development of such a process regarding expression vector design, cultivation conditions or inducer optimization to allow production of the active enzyme in large quantities.
Additionally, we also try to improve production of the SH in its native host R. eutropha. We aim at the development and the optimization of a bioprocess that allows cost-efficient production of enzymatically active, soluble [NiFe] hydrogenases from Ralstonia eutropha as well as both the hydrogenase and the reductase module independently from each other to overcome the problem of its so far low availability for both research and biotechnological purposes.