An international team of scientists, including two from Arizona State University, has taken a significant step closer to unlocking the secrets of photosynthesis, and possibly to cleaner fuels.

Plants and algae, as well as cyanobacteria, use photosynthesis to produce oxygen and "fuels," the latter being oxidizable substances like carbohydrates and hydrogen.

The ASU scientists working with collaborators at the Max Planck Institute at Mülheim a.d. Ruhr in Germany have been investigating the PSI reaction center.

They have made an important observation that is nut-shelled in the title of a paper published in the online Early Edition of the Proceedings of the National Academy of Sciences (PNAS).

Kevin Redding, an associate professor in the department of chemistry and biochemistry in the College of Liberal Arts and Sciences, is leading the research at ASU. His lab created mutations in a single-celled green alga (Chlamydomonas reinhardtii or 'Chlamy' for short).

Using these mutants, Redding and collaborators have shown that the primary light-triggered electron transfer event in the PSI reaction center can be initiated independently in each of its parallel branches. At the same time, they showed that PSI has two charge separation devices that effectively work in parallel to increase the overall efficiency of electron transfer.

"Although we knew that both branches were being used in PSI, and that our mutations had an effect upon the relative use of each pathway, what we did not know was how these mutations were having their effect," Redding explained. "Unraveling that has led to the discovery of how charge separation - the moment when electromagnetic energy is converted to chemical energy - actually occurs."

"This is Kevin Redding in his lab at Arizona State University. Together with coworkers from the Max Plank Institute, he has taken a significant step closer to unlocking the secrets of photosynthesis. (Credit: Mary Zhu)"

Source: Arizona State University