1. Photobiological Hydrogen Production Using Bioengineered Algae

2. Outline

3. Why Hydrogen? Highest energy/mass density of all known fuel types Produced Domestically Sustainable (if produced from water) Environmentally Friendly Fuel Cell: No pollutants or greenhouse gases ICE: only (NOx)

4. Chlamydomonas reinhardtii Single-celled green Algae 1939: German researcher Hans Gaffron discovered hydrogen metabolism Hydrogenase Catalyzed reaction, active only in absence of oxygen

5. Low light conversion effiency (~10%) Oxygen production inhibits Fe-hydrogenase Has not yet been overcome after 60 years of research

6. A hydrogen-producing C. reinhardtii culture.

7. Photosystem II Oxidation of Indegenous Cellular Substrate

8. Hydrogenase-related electron transport pathways in green algae.

11. Coordinated photosynthetic and respiratory electron transport and coupled phosphorylation during H2 production.

12. Regulation of Hydrogenase Grown under photo-autotrphopic condions algae neither consume or produce hydrogen Fe hydrogenase gene induced upon incubation of cells under anaerobic conditions in the dark, or S deprivation Results suggest oxygen is a positive suppresser of Fe hydrogenase gene expression at transcriptional level

13. Possible Solutions to Current Limitations Low light conversion efficiency: Truncate chlorophyll antenna size of PS-II using RNAi method Availability of reduced Ferrodoxin for Fe-Hydrogenase: Change Ferrodoxin affinity for (FNR) without affecting Fe-hydrogenase interaction

17. The Future http://www.toyota.com/fuelcell/