Using genetic sleight of hand, researcher Xinyao Liu and professor Roy Curtiss at Arizona State University's Biodesign Institute have coaxed photosynthetic microbes to secrete oilbypassing energy and cost barriers that have hampered green biofuel production. Their results appear in this week's advanced online issue of the Proceedings of the National Academy of Sciences or PNAS.
The challenges of developing a renewable biofuel source that is competitive with the current scalability and low-cost of petroleum have been daunting. "The real costs involved in any biofuel production are harvesting the fuel precursors and turning them into fuel," said Roy Curtiss, director of the Biodesign Institute's Center for Infectious Diseases and Vaccinology and professor in the School of Life Sciences. "By releasing their precious cargo outside the cell, we have optimized bacterial metabolic engineering to develop a truly green route to biofuel production."
Photosynthetic microbes called cyanobacteria offer attractive advantages over the use of plants like corn or switchgrass, producing many times the energy yield with energy input from the sun and without the necessity of taking arable cropland out of production.
Lead author Xinyao Liu and Curtiss, applied their expertise in the development of bacterial-based vaccines to genetically optimize cyanobacteria for biofuel production. Last year, they were able to modify these microbes, priming them to self-destruct and release their lipid contents. In the group's lastest effort however, the energy-rich fatty acids were extracted without killing the cells in the process.
"In China, we have a saying," Liu says. "We don't kill the hen to get the eggs." Rather than destroying the cyanobacteria, the group has ingeniously reengineered their genetics, producing mutant strains that continuously secrete fatty acids through their cell walls. The cyanobacteria essentially act like t
|Contact: Joe Caspermeyer|
Arizona State University