Enhanced Biological Hydrogen and Algal Biofuel Production from Ferredoxin Manipulations

Algae are one of the most promising long-term and sustainable sources of biomass. This biomass can be converted into biofuel byproducts. Major roadblocks for commercializing algal biofuels, however, prevent this technology from becoming viable in the market place. The first two years of this research study have cut costs of biofuels through genetic modification of algae, enhancing and automatically excreting the lipids. This current study looks to further the practicality of algal biofuels by introducing a second fuel byproduct, hydrogen gas. This research study is one of the first to attempt multiple byproducts from the same algal biomass.

Ferredoxins (FDX) are electron carriers found in plants utilized in biological hydrogen production. It was hypothesized that a forced electron pathway through  super-efficient FDX1 would generate a sustainable source of biological H₂ for use in fuel cells. It was found that enhancing FDX1 inhibiting ferredoxin NADP⁺ reductase generated 0.012 kg of H₂/m² per day for every 0.2 mm layer of algae. This means 60 kg of H₂ can be produced from one cubic meter of algae per day. Moreover, results showed that H₂ production had no effect on lipid production, thus proving that both byproducts could be collected simultaneously. A prototype algae cultivation raceway track, CACBA, was built to test this method at a potential commercial scale. Using this track, H₂ production was optimized at $0.89/1.00kg. In the future, excess biomass after collection of both lipids and hydrogen gas will be tested for pharmaceutical pigment extraction.