Marc Nowaczyk which everted from the Ruhr University to the University of Rostock. The current works were partly made in Bochum.
Photo Credit: ITMZ University of Rostock
Researchers question the way photosynthesis works.
A research team from the University of Cambridge, the University of Rostock and the Ruhr University Bochum succeeded for the first time in obtaining electrons directly from the early stages of photosynthesis. This breakthrough questions the previous model for the basic functioning of photosynthesis and has the potential to revolutionize the development of solar cells based on biological catalysts. The research work was published in the renowned journal Nature from 22. Published March 2023.
Manufacture hydrogen with sunlight
Biological catalysts, so-called enzymes, have long since determined our everyday life. For example, they are used as additives in detergents, they refine food or are used in large-scale processes to produce medicines or raw materials for the chemical industry. Compared to chemical catalysts, they have the advantage that they only react with very specific raw materials and therefore produce very specific products. In addition, biological catalysts are never based on precious metals or other rare raw materials. "In nature, solutions have always been established that are not limited by the availability of raw materials," says Prof. Dr. Marc Nowaczyk, head of the chair for biochemistry at the University of Rostock and co-author of the study, who did part of the work at the Ruhr University Bochum as part of the graduate school Microbial Substrate Conversion, MiCon for short.
But biological catalysts can also be used to generate energy, for example to produce hydrogen with sunlight. Nature also provides a blueprint for this with the process of photosynthesis. Almost all life is directly or indirectly dependent on the conversion of light energy by plants, algae or certain bacteria that produce biomass from the carbon dioxide of the atmosphere. More precisely: In photosynthesis, the conversion of carbon dioxide and water with the aid of light supplies creates sugar molecules and oxygen. All fossil fuels such as coal, oil or gas are ultimately based on the energy conversion by photosynthetic organisms. The team around Marc Nowaczyk examines the molecular basis of photosynthesis and tries to use this as a basis to design biological solutions for the conversion and storage of energy. "In an interdisciplinary approach, we want to develop hybrid systems that use biological catalysts and light energy to produce hydrogen as an energy source," explains Marc Nowaczyk.
Research brings surprises
However, a prerequisite for this is a precise understanding of how the biocatalysts involved in photosynthesis work, the so-called photo systems. The present study shows that this can bring surprises. So far, it was assumed that the photo systems would inevitably have to have high energy losses due to their design principle. While the first steps of energy conversion are still highly efficient (up to 99 percent) Much of the energy is already lost at the photo system level through the transportation of electrons (about 60 percent energy loss) and at the end of the process, depending on the organism, less than one percent of the original light energy is chemically bound. In the present study, however, it could be shown that the high losses could in principle be avoided. Because with ultra-fast spectroscopy it was proven that certain synthetic mediators - small chemical mediator molecules - can tap electrons out of the photo systems at a much earlier point in time than previously thought. "Our results enable completely new concepts for the design of biological solar cells, which - at least in theory - could significantly improve efficiency," says Marc Nowaczyk. "Until this is actually used in practice, it is still a long way and requires further research," he concludes.
Published in journal: Nature
Source/Credit: Ruhr University Bochum / University of Rostock | Kristin Nölting
Reference Number: bio032323_01