S84: Metabolic engineering of cyanobacteria for the production of specialty chemicals

Finding a sustainable alternative for today’s petrochemical industry is a major challenge facing chemical engineers and society at large. To be sustainable, routes for converting carbon dioxide and light into organic compounds for use as both fuels and chemical building blocks must be identified, understood, and engineered. Advances in metabolic engineering, synthetic biology, and other biological engineering disciplines have expanded the scope of what can be produced in a living organism. As in other engineering disciplines, synthetic biologists want to apply a general understanding of science (e.g. biology and biochemistry) to construct complex systems from well-characterized parts (e.g. DNA and protein). Once novel synthetic biological systems (e.g. enzymes for biofuel synthesis) are constructed, they must be engineered to function inside evolving cells without negatively impacting the host’s physiology.

This talk will present research efforts to metabolically engineer strains of the cyanobacterium Synechococcus sp. PCC7002 for production of chemicals directly from sunlight and carbon dioxide. Our work is motivated by the potential to bypass recalcitrant aspects of biomass processing and couple chemical production with waste remediation. PCC7002 is an ideal system for several reasons. The PCC7002 genome has been sequenced and is publically available. It is one of the fastest growing species (autotrophic doubling time ~3.5hr), is halotolerant, can grow under a wide temperature range (20-38°C), is genetically tractable, and naturally transformable. We are currently engineering PCC7002 to produce a range of high-value chemicals. Here, I will discuss recent efforts to produce medium chain length alpha-olefins and 3-hydroxypropionate in PCC7002.