Revealing the Molecular Mechanism of Fertilizer Production in Nature for Decentralised Fertiliser Production in Photobioreactors

In this project I will apply fundamental research to develop biotechnological decentralised fertiliser production as a sustainable alternative to the energy demanding Haber-Bosch-Process where N2 is split in presence of H2 at 500 °C at pressures of 300 atmospheres.In Nature special proteins, the redox enzymes nitrogenases, catalyse this key process of N2 fixation to fertiliser with high efficiency and at ambient conditions.

However, the structural understanding of this enzymatic catalysis is based on snapshots of potential reaction intermediates.I will follow the changes in molecular structure in nitrogenases during turnover to understand the nitrogen fixation reaction mechanism.

Then I will use the obtained molecular information to increase the ammonia production efficiency of nitrogenases via targeted site directed mutagenesis.

Finally, two approaches will be explored to couple these improved nitrogenases to light harvesting in photobioreactors: introducing the improved nitrogenases into cyanobacteria cell cultures and adding biocompatible carbon and polymer dots to the native host cells. The resulting cell factories will produce fertilizer from air and water using the energy provided by the sun.

This approach will demonstrate decentralised fertiliser production as a sustainable alternative to the Haber-Bosch-Process, providing users with constant and local supply of sustainable fertilizer.