Improving Cyanobacterial Synthesis of Alkanes

The Science

Cyanobacteria are important photoautotrophic organisms that can capture carbon dioxide and convert it into a suite of organic compounds such as high-density liquid fuels. Using synchrotron Radiation-based Fourier transform infrared (SR-FTIR) spectromicroscopy as a high-throughput imaging method, researchers tracked metabolic phenotypes of Synechocystis 6803, which was engineered for enhanced production of alkanes and free fatty acids. Multivariate SR-FTIR data analysis revealed biochemical shifts in the engineered cells. These results demonstrate the applicability of SR-FTIR spectromicroscopy for rapid metabolic screening and phenotyping of live individual cells. The research was conducted using resources at the Advanced Light Source at Lawrence Berkeley National Laboratory.

Summary

Cyanobacteria, like algae and plants can use solar power to capture CO2 via the Calvin–Benson–Bassham (CBB) cycle and convert it to a suite of organic compounds.

As opposed to microalgae that can accumulate large amounts of triacylglycerols (TAGs) as storage lipids, the cyanobacteria studied to date produce little or no TAGs, but their FAs are directly shuttled to membrane lipid synthesis. Conversely, cyanobacteria, which are Gram-negative bacteria, are well suited for synthetic biology and metabolic engineering approaches aimed at redirecting carbon flux in lipid metabolism to specific biofuel molecules, including ethanol, butanol, biodiesel, and hydrocarbon biofuels.

Phototrophic biosynthesis of high-density liquid biofuels in cyanobacteria could augment microbial production of biodiesel and hydrocarbons in heterotrophic bacteria such as Escherichia coli.

BER Program Manager

Amy Swain

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]

References

Hu, P., S. Borglin, N. A. Kamennaya, L. Chen, H. Park, L. Mahoney, A. Kijac, G. Shan, K. L. Chavarría, C. Zhang, N. W. T. Quinn, D. Wemmer, H.-Y. Holman, and C. Jansson.  2013. “Metabolic Phenotyping of the Cyanobacterium Synechocystis 6803 Engineered for Production of Alkanes and Free Fatty Acids,” Applied Energy 102, 850–59. DOI:/10.1016/j.apenergy.2012.08.047.