Building a Better Biofuel Production Platform: Engineering Metabolic Control Techniques to Control the Photosynthetic Cyanobacterium Synechocystis Sp. PCC 6803

Building a Better Biofuel Production Platform:

Engineering metabolic control techniques to control the photosynthetic cyanobacterium Synechocystis sp. PCC 6803

Stevan C. Albers¹, Christie A.M. Peebles^1,2

¹Cell and Molecular Biology Graduate Program, ²Department of Chemical and Biological Engineering

Colorado State University, Fort Collins, Colorado

Biofuel production in microorganisms has great potential to fulfill this nation’s need for fungible “green” transportation fuels. Because of the simplicity of bacterial cells, photosynthetic cyanobacteria make good candidates as a platform for biofuel production. Many metabolic engineering techniques and procedures have been optimized for various heterotrophic bacteria, but few techniques have been designed with autotrophic cyanobacteria in mind. Designing rational control systems in cyanobacteria is the first step in controlling pathways that utilize carbon dioxide to produce long chain hydrocarbon like molecules. Understanding and controlling the metabolic pathways that produce these molecules is critical to demonstrate the true functionality of these photosynthetic organisms.

Synechocystis sp. PCC 6803 is a very versatile organism for a variety of reasons. It is a photoautotrophic bacterium for which it’s haploid genomic DNA has been sequenced. Because of the simplicity of cyanobacterial cells, higher system efficiencies can be reached when compared to other photosynthetic algal cells. Manipulation techniques like natural uptake, electroporation, and homologous recombination are well annotated in this species. The organism is capable of rapid doubling times while harboring such metabolic pathways as flavonoid, clavulanic acid, and fatty acid biosynthesis while also harboring pathways capable of toluene, atrizine, DDT degradation. Our group plans to focus on understanding specific pathways endemic to Synechocystis and utilizing these pathways to further the molecular engineering toolset available for this versatile organism. Specifically, we will be discussing the design, construction, and expression of various promoter constructs capable of rational gene control in Synechocystis sp. PCC 6803. This talk will focus on our progress to date.