Friday, February 24, 2006
Bioengineered hydrogen-producing algae
Sam Jaffe at Wired reports that researchers at the University of California at Berkeley have engineered a strain of algae that could, with further refinements, produce vast amounts of hydrogen via photosynthesis.
Blue-green Algae floating on the surface of the world's oceans already produces the majority of the world's oxygen supply via photosynthesis. This new strain of algae, known as C. reinhardtii, has truncated chlorophyll antennae within the chloroplasts of the cells, which serves to increase the organism's energy efficiency. In addition, it makes the algae a lighter shade of green, which in turn allows more sunlight deeper into an algal culture and therefore allows more cells to photosynthesise.
"An increase in solar conversion efficiency to 10 percent... is thought to be enough to make the mass culture of algae viable," says Juergen Polle, a former student of Melis’ who now does research on algae at the City University of New York, Brooklyn.
Polle points out that Melis has probably already reached that 10 percent threshold. But further refinements are still required before C. reinhardtii farms would be efficient enough to produce the world’s hydrogen, which is Melis' eventual goal.
Currently, the algae cells cycle between photosynthesis and hydrogen production because the hydrogenase enzyme which makes the hydrogen can’t function in the presence of oxygen. Researchers hope to further boost hydrogen production by using genetic engineering to close up pores that oxygen seeps through.