Genetically Enhanced Nitrogen Fixation with Algae Biofilms

This project will develop an algae-base nitrogen fixation process for commercial ammonia production for the agronomy market. This process operates under standard conditions. The technology utilizes a whole-cell mutant algae strain grown on an electrode surface and takes advantage of enzymatic pathways to make ammonia at standard conditions. The primary inputs are electricity and water. Compared to the current Haber-Bosch process, the proposed technology has less capital costs, generates ammonia at a lower cost and permits distributed on-demand production of fertilizer on a local scale, enabling many smaller fertilizer plants to be built at lower cost and bridge the gap in availability. The objectives of this project are increase the production rate to 25 µmole ammonia per cm2 per hour through genetic engineering, Increase the scale of the project by an order of magnitude, 50 cm2 electrode to 500 cm2. The algae mutant expresses nitrogenase through a high population of heterocyst cells. Genetic engineering at the University of Utah will be used to increase the expression of the nitrogenase enzyme in the cell itself. The scale up of the process will require a new cell to be constructed and an examination of the process conditions. The incorporation of opaque electrodes and maintaining enough light for the algae is seen as a unique challenge. The proposed method will be the first continuous process, where the enzymes are stimulated for increased production and the product is expressed extracellularly.