One of the broad themes for investigation in our lab is using synthetic biology to build molecular machines that can utilize the carbon dioxide often considered as an industrial waste product from power generation. While the release of this CO2 into the atmosphere can cause a host of problems including global climate change and ocean acidification, concentrated carbon dioxide represents a rich food source to a cyanobacterium. With energy from sunlight, cyanobacteria can metabolize CO2 via photosynthesis for growth and generation of value-added products.
However, natural strains of Synechocystis are not optimized for this industrial use. They are limited in the speed at which they take up CO2, and valuable fractions of biomass such as alkanes, pigments, and succinic acid do not make up the majority and are not easily separable from the other components.
Synthetic biology tools will allow us to genetically alter cyanobacteria to produce greater proportions of their biomass as the most valuable and useful fractions, by regulating the gene expression of native and non-native pathways leading to desired and undesired products. They can allow us to ease separation of valuable compounds from biomass by ensuring that they are exported from cells into the culture medium.
At the same time, we are seeking ways to increase the rate at which cyanobacteria are capable of taking up CO2. This is a multi-pronged effort that includes designing new bioreactors for improved microalgal growth, identifying new robust and fast-growing strains, and the use of synthetic biology to create mutants that more efficiently distribute solar energy among individuals within a culture.