A team of scientists, including many in the Molecular Biophysics and Integrated Bioimaging Division, uncovered new details about the reaction that powers photosynthesis. Understanding this reaction could lead to world-changing advances in technology, medicine, or energy––and also gives insight into how the enzyme photosystem II produces the oxygen we breathe. Their latest work was recently published in Nature Communications and two of the authors, Vittal Yachandra and Philipp Simon, spoke with Strategic Communications about that, shooting stuff with lasers, and why they chose this field of research.
Heinz Frei, a senior scientist in Biosciences’ Molecular Biophysics and Integrated Bioimaging (MBIB) Division, seeks to engineer devices that emulate photosynthesis – the sunlight-driven chemical reaction that green plants and algae use to convert carbon dioxide (CO2) into cellular fuel. If the necessary technology could be refined past theoretical models and lab-scale prototypes, this idea, known as artificial photosynthesis, has the potential to generate large sources of completely renewable energy using the surplus CO2 in our atmosphere.
Frei’s team has developed an artificial photosynthesis system, comprised of nanosized tubes, that appears capable of performing all the key steps of the fuel-generating reaction. Their latest paper, published in Advanced Functional Materials, demonstrates that their design allows for the rapid flow of protons from the interior space of the tube, where they are generated from splitting water molecules, to the outside, where they combine with CO2 and electrons to form the fuel. Fast proton flow is essential for efficiently harnessing sunlight energy to form a fuel.
An article published in the Computing Sciences News Center describes how Biosciences researchers are using a superfacility framework of experimental instrumentation with computational and data facilities to unravel the long-standing mystery of how Photosystem (PSII) works. The protein complex plays a crucial role in photosynthesis, making it key to achieving artificial photosynthesis that could produce fuels using sunlight and carbon dioxide. Researchers—led by Vittal Yachandra, Junko Yano, and Jan Kern in Molecular Biophysics and Integrated Bioimaging (MBIB)—recently began using ESnet to enable real-time processing of experimental data collected at the SLAC National Accelerator Laboratory’s Linac Coherent Light Source (LCLS) at NERSC to observe this water-splitting protein in action. Asmit Bhowmick, a postdoctoral researcher in the laboratory of MBIB senior scientist Nicholas Sauter, is quoted in the article.
The unicellular green alga Chromochloris zofingiensis has the ability to shift metabolic modes from photoautotrophic (synthesizing food using light as energy source) to heterotrophic (obtaining food and energy from exogenous sources) in response to carbon source availability in the light. It also has the capacity—under certain conditions—to produce high amounts of commercially relevant bioproducts: notably, the ketocarotenoid astaxanthin, used in feed, cosmetics, and as a nutraceutical, and triacylglycerol (TAG) biofuel precursors.
Understanding how photosynthesis and metabolism are regulated in algae could, via bioengineering, enable scientists to reroute metabolism toward beneficial bioproducts for energy, food, and human health. To that end, Berkeley Lab Biosciences researchers used C. zofingiensis as a simple algal model system to investigate conserved eukaryotic sugar responses, as well as mechanisms of thylakoid breakdown and biogenesis in chloroplasts.
Using the SLAC National Accelerator Laboratory’s Linac Coherent Light Source (LCLS) X-ray laser, an international collaboration led by scientists at Berkeley Lab and SLAC captured the all four stable oxidation states of photosystem II— plus two transitional states—at natural temperature and the highest resolution to date.