Cyanobacterial Biology and Biotechnology
Cyanobacteria (Fig. 1) are some of the simplest microbes capable of harnessing energy from sunlight and are among the most evolutionarily ancient organisms. Indeed, cyanobacterial biochemistry, acting over millions of years, radically altered the atmosphere and enabled life as we know it on Earth today. It seems therefore fitting that cyanobacteria could be an important component to help us address some of today’s urgent energy and atmospheric problems.
We are a young lab with prior experience engineering cyanobacterial strains that can convert solar energy into the biofuel hydrogen gas, or excrete bioindustrially-compatible sugars for downstream applications. Our aim is to continue to utilize traditional engineering and emerging synthetic biological tools to refine our capacity to compartmentalize and control the complex metabolism of cyanobacteria. These tools have allowed us to probe the flexibility of photosynthetic metabolism and generate strains with emergent properties that have broader implications for understanding dynamic feedback and regulation between metabolism and light gathering in green microbes and plants.
For example, we have recently designed a strain of cyanobacteria that can export a significant fraction of the carbon it fixes (up to 85%) as sucrose. This approach is promising as a potential alternative to land-based crops for sugar production (Fig. 2), as this level of productivity could exceed sugar output from sugarcane or corn if it could be scaled.
Furthermore, this system also allows us to place a novel metabolic burden on the cell in a tunable fashion and investigate the response – an approach that can reveal aspects of the basic physiology of the system. Counter-intuitively, we have found that these cyanobacterial strains respond by upregulating their photosynthetic capacity and increasing their CO2 fixation rate to help keep pace with the demand. Understanding this phenomena, and other adaptive responses, could lead to a better understanding of how to poise metabolism for maximal photosynthetic efficiencies and the most effective biological sustainable solutions. Ongoing projects in the lab aim to contribute broadly in the areas of alternative energy development, underst