Solar energy is a sustainable resource exceeding human energy demands by >3 orders of magnitude. If this diffuse energy can be concentrated and stored, it has the capacity to provide for human energy needs. The biological transformation of light to chemical energy (photosynthesis) is limited by the rate of carbon reduction. The goal of this project is to engineer pathways for diverting energy from carbon reduction to alternative sinks. Our strategy is to engineer an intercellular, plug and play platform that allows electrons and/or reduced chemicals to move from photosynthetic cells to engineered fuel production modules, bypassing the inefficient carbon-fixing catalyst RuBisCO. This will be achieved by increasing flux through natural electron dissipation pathways, creating electrical connections between cell types, and employing a soluble redox shuttle to transfer reducing equivalents between cells. This international and interdisciplinary project is building bridges between the US and UK scientific communities in critical areas of synthetic biology, photosynthesis, electro-chemistry, catalysis, and metabolic regulation.
The scientific goals are organized around 4 specific aims.
- Characterize components and control flux through the natural photosynthetic pathways in the cyanobacteria Synechocystis.
- Construct artificial systems to sink reducing equivalents from photosynthesis.
- Develop artificial means to move reducing equivalents outside the cell.
- Produce artificial fuel production modules that require only reducing equivalents and CO2.
The project represents a radical approach to surpass natural photosynthesis by engineering a modular division of labour through electrical/chemical connectivity. The aims are devised to generate transformative research for technological applications and enable the discovery of fundamental science. Our goal, therefore, is to establish a platform to open a vast new frontier to develop new modular photosynthetic technologies.