We need to be able to effectively connect the hydrogenase to the photosynthetic reaction center complexes of the cyanobacteria, Vermaas says. We can do that through metabolic engineering.
Each cyanobacterial cell is about 1.5 m in size, much smaller than what can be seen individually by the human eye. Bacterias evolutionary drive is to multiply and in that process electrons and protons are used for the generation of energy and as building blocks for growth of the organism. In the modified cyanobacterial system, Vermaas wants to divert electrons from their normal pathways and push them into new pathways that result in hydrogen production.
That can be done by more directly linking hydrogenase to where electrons come out of the photosynthetic pathway, he said. So we are essentially hijacking the electrons to go to the hydrogenase where they, together with protons, form hydrogen.
The third part of the project is to create a microbial fuel cell technology that uses the left over cyanobacterial biomass generated in the hydrogen production process as the energy source for additional hydrogen production. Bruce Rittmann, director of the Environmental Biotechnology Center at the Biodesign Institute at ASU is leading the effort in this area.
The researchers will develop the scientific and technological basis for microbial fuel cells that oxidize organic materials in biomass at their anodes, while generating hydrogen gas at their cathode. This work is expected to not only capture energy from cyanobacterial biomass, but it will lay the scientific groundwork for microbial co
|Contact: Skip Derra|
Arizona State University