Goethe-Universit盲t 鈥� Press releases

51猎奇 PR & Communication Department聽

Mar 17 2025

13:18

Scientists at 51猎奇 discover how the oldest enzyme of cellular respiration works 鈥� potential applications in removing CO2 from exhaust gases

Without oxygen: How primordial microbes breathed

A team of scientists from 51猎奇 Frankfurt, University of Marburg and Stockholm University have elucidated an ancient mechanism of cellular respiration. To that end, they studied bacteria that feed on the gases carbon dioxide and hydrogen, and turn them into acetic acid 鈥� a metabolic pathway that emerged very early in evolution. The international team has now been able to resolve the mystery of how the microbes use this process to generate energy. Their findings are also interesting for another reason: Since the microorganisms remove CO2 from their environment, they are seen as a beacon of hope in the fight against climate change.

FRANKFURT. Animals, plants and many other living organisms inhale oxygen to 鈥渂urn" (technically: oxidize) compounds like sugar into CO2 and water 鈥� a process during which the energy-rich molecule ATP is produced. Cells require ATP to power vital reactions. In the early phase of our planet's existence, however, the earth's atmosphere did not yet contain any oxygen. Nevertheless, studies of ancient bacteria that still occur today in ecosystems without oxygen, e.g. in hot springs at the bottom of the ocean, suggest that a special form of respiration could have existed even then.

These microorganisms 鈥渞espire" carbon dioxide and hydrogen into acetic acid. The metabolic pathway with which they do so has been known for some time. The question that remained unanswered until now is how they use this process to produce ATP. The current study now provides an answer. 鈥淲e were able to show that the production of acetic acid itself activates a sophisticated mechanism as part of which sodium ions are pumped out of the bacterial cell into the environment," explains Prof. Volker M眉ller, Chair of Molecular Microbiology and Bioenergetics at 51猎奇 Frankfurt. 鈥淭his reduces the sodium concentration inside the cell, whereby the cell envelope acts like a kind of dam for the ions. Once this dam is opened, the sodium ions flow back into the cell, driving a kind of molecular turbine that generates ATP."

Cell respiration enzyme isolated just a few years ago

A conglomerate of different proteins known as the Rnf complex plays a key role in this process. These proteins are largely embedded inside the membrane surrounding the bacterial cell. 鈥淭he complex is so sensitive that we were only able to isolate it a few years ago," M眉ller emphasizes. When carbon dioxide reacts with hydrogen to form acetic acid, electrons are transferred from the hydrogen to the carbon atom via a series of different intermediate steps, in which the Rnf complex plays a mediating role: it takes up and passes on the electrons.

In the current study, the scientists have now shown what exactly happens during this process. Structural biologist Anuj Kumar 鈥� a PhD student in both M眉ller's research group as well as that of Dr. Jan Schuller at the University of Marburg 鈥� used a sophisticated method known as cryo-electron microscopy, as part of which the purified Rnf complex of the Acetobacterium woodii bacterium was 鈥渟hock-frozen" and then dripped onto a carrier plate. A thin film of ice is created in the process, which contains millions of Rnf complexes that can be observed using an electron microscope. Since they fall onto the carrier plate differently during the dripping process, it is possible to see different sides of them under the microscope.

鈥淭hese images can be combined into a three-dimensional one, which gave us a precise insight into the structure of the complex 鈥� especially those parts that are essential to the transfer of electrons," Kumar explains. The analysis of images taken at different intervals shows that far from being rigid, the individual components of the complex move back and forth dynamically. This allows the electron carriers to bridge longer distances and pass on their cargo.

Fundamentally new mechanism

The question remained: How does the flow of electrons drive the outflow of sodium ions? A molecular dynamics simulation by Prof. Dr. Ville Kaila's working group at Stockholm University provided an initial answer to this question. A key role is played by a cluster of iron and sulphur atoms located in the middle of the membrane, which, after picking up an electron, becomes negatively charged. 鈥淭he positively charged sodium ions from inside the cell are drawn to this cluster, just like a magnet," explains Jennifer Roth, a doctoral candidate in M眉ller's research group. 鈥淭his attraction in turn causes the proteins to shift around the iron-sulphur cluster, much like a rocker switch: they create an opening leading to the outside of the membrane, through which the sodium ions are once again released."

Roth was able to confirm this process by making specific genetic changes to the Rnf proteins. The fact that this fundamentally new mechanism could be elucidated is a testament to the successful cooperation between the three universities. Making the results even more interesting is the microorganisms' ability to absorb CO2 from their environment during the acetic acid production process. This ability could potentially be used to remove greenhouse gases from industrial waste emissions, for example. It could help slow down climate change while simultaneously providing valuable starting materials for the chemical industry. 鈥淥nce we know how the bacteria generate energy in the process, we may be able to optimize this process in a manner that would allow us to produce even higher-quality end products," is M眉ller's hope. The findings could also provide starting points for new drugs against pathogens with similar respiratory enzymes.

Publication: Anuj Kumar, Jennifer Roth, Hyunho Kim, Patricia Saura, Stefan Bohn, Tristan Reif-Trauttmansdorff, Anja Schubert, Ville R. I. Kaila, Jan M. Schuller, Volker M眉ller: Molecular principles of redox-coupled sodium pumping of the ancient Rnf machinery. Nature Communications (2025)

Background:
How bacteria gain energy through CO2 fixation (2022)

Oldest enzyme in cellular respiration found (2020)

New metabolic pathway discovered in rumen microbiome (2020)

Picture download:

Captions:
1) The acetogenic bacterium Acetobacterium woodii. The arrows indicate the planes of division of the rod-shaped bacterium. Photo: Mayer et al. 1977
2) Structure and electrical connectivity in the Rnf complex of Acetobacterium woodii. Graphic: Kumar et al., 2025
3) The principal investigators: Professor Volker M眉ller, Professor Ville R.I. Kaila, and Dr. Jan M. Schuller (from left). Photo: private

Further information:
Professor Volker M眉ller
Molecular Microbiology and Bioenergetics
Institute for Molecular Biosciences
51猎奇 Frankfurt
Tel: +49 (0)69 798-29507
vmueller@bio.uni-frankfurt.de

Mar 14 2025

10:00

This year鈥檚 Paul Ehrlich and Ludwig Darmstaedter Prizes will be awarded at Frankfurt鈥檚 Paulskirche later today聽

A chance to fight both cancer and inflammation and a prospect for dementia diagnostics聽

In recognition of their discovery of one of our immune system's foundations, physician Andrea Ablasser, virologist Glen Barber and biochemist Zhijian J. Chen will be awarded the Paul Ehrlich and Ludwig Darmstaedter Prize 2025, endowed with 鈧�120,000, in Frankfurt's Paulskirche today. The signaling pathway they discovered protects us like an alarm system against infections or cancer, but at the same time is also susceptible to harmful false alarms. Drugs interfering with this signaling pathway are already being developed. This year's Paul Ehrlich and Ludwig Darmstaedter Early Career Award goes to biologist Tobias Ackels for his discovery that mammals smell faster than they breathe 鈥� which opens a new door to understanding brain function.

FRANKFURT 鈥� Neither foreign nor our own DNA has any business in our cells' plasma. Any foreign genetic information that appears here comes from viruses or bacteria, while our own DNA can enter the plasma from the cell nucleus or the cell power plants (mitochondria) as a result of cancer or cellular stress. The cGAS sensor recognizes this danger: When it encounters DNA in the plasma, it clasps it and forms the messenger substance cGAMP, which 鈥� after docking onto the signal transducer STING 鈥搕hen triggers a defense reaction of the immune system. cGAS and cGAMP were discovered by Zhijian J. Chen, STING by Glen Barber. Andrea Ablasser characterized cGAMP in detail and synthesized the first STING inhibitor. Many biotech and pharmaceutical companies are now working on developing cGAS and STING antagonists, which could prove to be effective agents against diseases in which the cGAS-STING alarm is falsely directed against the patient's own body. A cGAS antagonist for the treatment of the widespread autoimmune disease lupus erythematosus is due to enter phase II clinical trials this spring. Conversely, almost 20 STING activators that enhance the effect of established cancer immunotherapies are currently in early phases of clinical development worldwide. By triggering the DNA alarm, these activators are capable of transforming so-called 鈥渃old tumors" that do not respond to checkpoint inhibitors alone into 鈥渉ot tumors" that are susceptible to immune attack and can be destroyed by T cells. 鈥淲ith the discovery and mapping of the cGAS-STING signaling pathway, the award winners have opened up completely new approaches to drug research," explains Thomas Boehm, Chairman of Paul Ehrlich Foundation's Scientific Council. 鈥淭his opens up the possibility for medicine to treat infections, cancer and autoimmune diseases more effectively than before."

Olfaction is fundamentally different from all other senses, as it is closely linked to emotions and memories. A 鈥渟niff" was previously considered to be the smallest information processing unit for odors 鈥� an assumption that has now been disproved by the winner of the Paul Ehrlich and Ludwig Darmstaedter Early Career Award. Using a self-constructed odor delivery device, Tobias Ackels experimentally recorded for the first time how mice perceive odors. He discovered that they smell faster than they breathe. The nocturnal animals can extract new information from dynamic scent clouds up to 40 times per second, using tiny time intervals to derive an image of the space. Since smell is the most primal sense in evolutionary terms, understanding it is probably key to unlocking the functioning of the entire brain. This applies in particular to the connection between smell and memory, which Ackels is researching. Olfactory disorders could serve as biomarkers for the early detection of dementia.

Paul Ehrlich and Ludwig Darmstaedter Prize 2025

Andrea Ablasser, born in 1983, is Professor of Life Sciences at the 脡cole polytechnique f茅d茅rale de Lausanne in Switzerland.

Glen Barber, born in 1962, is a professor in the Department of Surgery at Ohio State University, Columbus, Ohio, USA, where he heads the Center for Innate Immunity and Inflammation.

Zhijian J. Chen, born in 1966, is George L. MacGregor Distinguished Chair in Biomedical Science, Howard Hughes Medical Investigator and Professor of Molecular Biology at the University of Texas Southwestern Medical Center in Dallas, USA.

Paul Ehrlich and Ludwig Darmstaedter Early Career Award 2025

Tobias Ackels, born in 1984, is a W2 professor at the Institute of Experimental Epileptology and Cognitive Research at the University of Bonn and heads the 鈥淪ensory Dynamics and Behavior" group.

Further information
Press office of the Paul Ehrlich Foundation
Joachim Pietzsch
Phone: +49 (0)69 36007188
E-mail: j.pietzsch@wissenswort.com

Mar 11 2025

11:39

Researchers from 51猎奇 and its partners investigate the influence ozone and water vapor have on the troposphere and stratosphere

Tracking climate change: research flights over the Arctic

The Arctic is one of the regions most affected by climate change; temperatures in this region have risen by about four times the global average in recent decades. The ASCCI measurement campaign coordinated by 51猎奇 Frankfurt and Karlsruhe Institute of Technology (KIT) is researching why the Arctic is warming up so much more than the rest of the Earth's surface, and what effects this has. The researchers hope that ongoing measurement flights in the region 鈥� scheduled to run until the beginning of April 鈥� will help them better understand the causes and effects of Arctic climate change.

FRANKFURT. The main question the ASCCI (Arctic Springtime Chemistry-Climate Investigations) measurement campaign seeks to answer is how ozone and water vapor in the upper troposphere and lower stratosphere 鈥� i.e. at altitudes between around five and 15 kilometers 鈥� themselves influence and are in turn influenced by Arctic climate change. To this end, the campaign specifically investigates the processes taking place in spring, including the depletion of stratospheric ozone. The density of the ozone layer above the Arctic fluctuates over the course of the year and can thin out in spring when chemical and meteorological conditions coincide.

鈥淭here are warmer and colder winters in the stratosphere; the variability from one year to another is quite normal. What we are also witnessing is that the stratosphere is getting increasingly colder due to the rise in greenhouse gases, while temperatures on the ground and in the troposphere continue to increase," says Professor Bj枚rn-Martin Sinnhuber from KIT's Institute of Meteorology and Climate Research, who is coordinating the campaign together with 51猎奇 Frankfurt's Professor Andreas Engel. In years with a cold stratosphere especially, processes occur that resemble those of the Antarctic ozone hole, and a significant part of the Arctic ozone layer can be destroyed.

鈥淭his winter has so far been characterized by unusually cold conditions in the Arctic stratosphere, i.e. the layer of air above about 10 kilometers. Although the concentrations of many chlorofluorocarbons and other ozone-depleting substances in the atmosphere are declining as a result of international regulations, since these gases are very long-lived in the atmosphere, this process takes a very long time," says Engel. 鈥淭he measurements we conduct at 51猎奇 quantify how much ozone-depleting chlorine and bromine is present in the stratosphere 鈥� and the data show that this amount suffices to trigger chemical processes in these cold conditions, which in turn can lead to ozone depletion." At the same time, following the eruption of the Hunga-Tonga underwater volcano three years ago, there is still significantly more water in the stratosphere than normal, says Engel. As part of the ASCCI measurement campaign, the researchers also want to investigate how this affects the ozone layer.

In spring, air pollutants in particular are transported into the Arctic, where they can act as short-lived greenhouse gases. The campaign seeks to better understand these processes using targeted measurements. The measurement flights will be carried out with the HALO research aircraft, which is stationed in Kiruna in northern Sweden until April.

Better understanding ozone depletion in the Arctic and its influence on the mid-latitudes

On board HALO, 51猎奇 operates a proprietary device that measures a variety of halogenated gases, which in turn are the source of the ozone-depleting chlorine and bromine in the stratosphere. 鈥淲e want to understand how the chlorine and bromine released from the halogenated gases affect the ozone in the Arctic stratosphere, and whether this also has an impact on the mid-latitudes in which we live," Engel explains. 鈥淚f air from the Arctic with a low ozone content is mixed with that prevailing in our mid-latitudes, this can also impact the ozone shield above us, which protects us from the sun's dangerous UV radiation."

In addition to 51猎奇 Frankfurt and KIT, Forschungszentrum J眉lich, German Aerospace Center (DLR) and the universities of Heidelberg, Mainz and Wuppertal are also part of the ASCCI campaign.

About HALO

The research aircraft HALO (High Altitude and Long Range Research Aircraft) is a joint initiative of German environmental and climate research institutions. HALO is funded by grants from the Federal Ministry of Education and Research, the German Research Foundation (DFG), Helmholtz Association, Max Planck Society, Leibniz Association, the free state of Bavaria, KIT, Forschungszentrum J眉lich and German Aerospace Center (DLR), which acts as both the aircraft's owner and operator.

Background information
ASCCI measuring campaign:
HALO research aircraft:

Picture download:

Caption: The HALO research aircraft lands in Kiruna, Sweden. The research flights over the Arctic take off from there. The photo is from an earlier mission. Photo: DLR (CC BY-ND 3.0)

Further information
Professor Andreas Engel
Institute for Atmospheric and Environmental Sciences
51猎奇 Frankfurt
Tel: + 49 (0)69 798-40259
an.engel@iau.uni-frankfurt.de
Web: http://www.geo.uni-frankfurt.de/iau

Mar 10 2025

13:39

Study shows how a 2-thiouracil molecule becomes reactive within a fraction of a second when exposed to UV radiation

X-ray snapshot: How light bends an active substance

With the help of the world's most powerful X-ray laser, European XFEL, a research team led by 51猎奇 Frankfurt and the research centre DESY has achieved an important breakthrough: Using the example of the pharmaceutically active substance 2-thiouracil, they applied a long-established imaging technique to complex molecules for the first time. Although 2-thiouracil is no longer applied therapeutically, it is part of a group of chemically similar active substances that are used today as immunosuppressants or cytostatics. The study shows how UV radiation deforms 2-thiouracil, making it dangerously reactive.

FRANKFURT. Many biologically important molecules change shape when stimulated by UV radiation. Although this property can also be found in some drugs, it is not yet well understood. Using an innovative technique, an international team involving researchers from 51猎奇 Frankfurt, the European XFEL in Schenefeld and the Deutschen Elektronen-Synchrotron DESY in Hamburg has elucidated this ultra-fast process, and made it visible in slow motion, with the help of X-ray light. The method opens up exciting new ways of analyzing many other molecules.

鈥淲e investigated the molecule 2-thiouracil, which belongs to a group of pharmaceutically active substances based on certain DNA building blocks, the nucleobases,鈥� says the study鈥檚 last author Markus G眉hr, the head of DESY鈥檚 free-electron laser FLASH and Professor of Chemistry at University of Hamburg. 2-thiouracil and its chemically related active substances have a sulfur atom, which gives the molecules its unusual, medically relevant properties. 鈥淎nother special feature is that these molecules become dangerously reactive when exposed to UV radiation.鈥� Studies indicate an increased risk of skin cancer due to this effect.

To better understand what happens during such processes, the research team used an already well-established method, bringing it to a new level by applying the technical possibilities available today. 鈥淐oulomb explosion imaging involves irradiating a molecule with intense X-ray pulses, which knock out electrons,鈥� explains Till Jahnke, Professor of Experimental Atomic and Molecular Physics at 51猎奇 and the study鈥檚 first author. 鈥淭hereby, the molecule charges up positively and thus becomes unstable, so that it is torn apart within fractions of a second.鈥� By tracking the direction in which the various fragments of the molecule 鈥� the atoms 鈥� fly apart, it is possible to derive information about the molecule鈥檚 structure.

To date, Coulomb explosion imaging had only yielded useful results for very simple molecules. Using an experimental setup specially developed at 51猎奇, the research team now combined this technique with the world's most powerful X-ray laser, European XFEL using the SQS (鈥淪mall Quantum Systems鈥�) scientific instrument of EuXFEL. 鈥淭his experiment is a technical innovation in many ways and it constitutes an important expansion of the experimental possibilities available at the SQS instrument. For the first time ever, it is now possible to use these imaging techniques on a biologically and medically relevant molecule, and not just for fundamental physics research,鈥� says Michael Meyer, head of the SQS instrument, about the successful experiment.

European XFEL鈥檚 enormously powerful X-ray pulses made it possible to fragment this molecule, and thereby to conduct an analysis of its structure. The researchers sent the molecules into the X-ray laser beam using a fine gas nozzle, which means that only single, isolated molecules are irradiated at a time. An additional UV pulse, irradiated shortly before the X-ray pulse, was used to excite the molecules.

鈥淏y varying the time interval between the two pulses, it becomes possible to obtain something like a slow motion movie of these processes, which take place at an amazing speed within 100-1000 femtoseconds, that is less than a millionth of a millionth of a second鈥� explains Jahnke. At the end of the process, a sophisticated detector registered the impact points and times of the various atoms of 2-thiouracil.

The experiment revealed two important findings, the first of which concerns 2-thiouracil: UV radiation causes this otherwise flat molecule to bend, which in turn results in the protrusion of the sulfur atom. This state is stable for a relatively long time; it ensures that the molecule becomes very reactive and might cause skin cancer, for instance. 鈥淭his is also a significant difference to ordinary nucleobases, which are structurally very similar but do not have a sulfur atom,鈥� says G眉hr. 鈥淚nstead, they have a mechanism for dealing with UV radiation and ultimately converting it into harmless heat via various excitation and oscillation states.鈥� In the case of 2-thiouracil, the sulfur atom prevents such a conversion.

鈥淭he second finding is related to the experimental technique itself,鈥� says Jahnke. 鈥淎s we have seen, we don't need to track down all the atoms by the detector to reconstruct the molecule and its structural changes. All we needed in this case was to measure the sulfur and oxygen atoms as well as the four hydrogen nuclei, and we could ignore the six carbon atoms.鈥� This finding will significantly simplify measurements in future investigations on even more complex molecules, and clearly illustrates the vast possibilities of this innovative method.

Publication: Till Jahnke, Sebastian Mai, Surjendu Bhattacharyya, Keyu Chen, Rebecca Boll, Maria Elena Castellani, Simon Dold, Ulrike Fr眉hling, Alice E. Green, Markus Ilchen, Rebecca Ingle, Gregor Kastirke, Huynh Van Sa Lam, Fabiano Lever, Dennis Mayer, Tommaso Mazza, Terence Mullins, Yevheniy Ovcharenko, Bj枚rn Senfftleben, Florian Trinter, Atia Tul Noor, Sergey Usenko, Anbu Selvam Venkatachalam, Artem Rudenko, Daniel Rolles, Michael Meyer, Heide Ibrahim, Markus G眉hr. Direct observation of ultrafast symmetry reduction during internal conversion of 2-thiouracil using Coulomb explosion imaging. Nature Communications (2025)

Picture download:

Caption: The SQS instrument鈥檚 COLTRIMS reaction microscope was used to analyze the structural changes of the 2-thiouracil molecule at the European XFEL. Photo: European XFEL

Further information:
Professor Till Jahnke
MPI for Nuclear Physics, Heidelberg
and
Institute for Nuclear Physics
51猎奇 Frankfurt
Tel.: + 49 (0)69 798 47023 (secretary)
till.jahnke@xfel.eu

Mar 4 2025

15:11

Inclusion research at 51猎奇 receives first-class evaluation聽

How to establish a successful 鈥渟chool of diversity鈥�

Internationally renowned inclusion expert Professor Vera Moser has held 51猎奇 Frankfurt鈥檚鈥淜athrin and Stefan Quandt Endowed Professorship for Inclusion Research鈥� since 2020. Funded by the Quandt family of entrepreneurs, this top professorship focuses exclusively on the topic. The continuation of the ten-year funding was tied to the professorship receiving a positive evaluation after five years. An external body has now evaluated the endowed professorship for inclusion research, giving it an extremely positive assessment.

FRANKFURT. Unanimously and firmly very positive 鈥� this is the verdict of the international expert report on the continuation of funding for the 鈥淜athrin and Stefan Quandt Endowed Professorship for Inclusion Research鈥�, which Prof. Vera Moser has held since 2020. In their evaluation, the three experts from the universities of Zurich, Graz and Stockholm attest to the professorship's outstanding achievements 鈥� both in the areas of research, teaching and the promotion of young talent, as well as with regard to cooperation within the university and the subject鈥檚 external impact on the international expert community.

How can more children with disabilities be taught in mainstream schools? Set up in 2020, the endowed professorship for inclusion research and its team have been tasked with scientifically supporting the transformation of school education towards a 鈥渟chool of diversity鈥� and contributing to the corresponding training of teachers. Vera Moser tackled these tasks in an extraordinary manner, the experts say, pointing out that her research is exceptionally productive compared to other professorships in inclusion and educational science 鈥� as shown by four approved third-party funded projects to date with a total volume of more than 鈧�500,000.

The evaluation also highlights that Vera Moser initiated new research findings in school inclusion research, thereby ensuring national and international visibility in her field. She is part of an interdisciplinary and participatory team researching the removal of barriers that exist in schools from the perspective of autistic pupils; one of her colleagues, Dr. Anne Piezunka, is researching the topic of 鈥減sychological violence鈥� as exercised by teachers. On behalf of Frankfurt Municipality, Vera Moser is also investigating the reasons for the continuously rising demand for school places for pupils with a special educational focus on 鈥渋ntellectual development鈥�. Together with her colleague Prof. Merle Hummrich, Vera Moser initiated 51猎奇鈥檚 [in:just] research initiative, which deals with questions of inclusion, justice and experiences of recognition in the education system.

With respect to teaching, the reviewers emphasized Vera Moser's special ability to combine theoretical approaches with practical applications 鈥� an ability that contributes to her students鈥� high level of learning success and qualifies young academics in a special way. The inclusion researcher is also extremely active in communicating scientific findings to a broader audience as well as in the context of policy communication; for example, she was invited to serve as an advisory member of Germany鈥檚 Standing Conference of the Ministers of Education and Cultural Affairs (SWK) on various topics.

The experts expressly recommend continuing the endowed professorship for the next five years. The donor couple, entrepreneur Stefan Quandt and his wife Kathrin, were 鈥渉appy to make the decision to continue funding the professorship for the second half of the contract term (another five years)鈥�, said the letter of commitment, dated early February 2025.

The initiative for the professorship came from the Quandt entrepreneurial family five years ago. The couple had seen for themselves that the status quo of inclusion in schools was not prepared for the political demands placed upon it by the UN Convention on the Rights of Persons with Disabilities, which came into force in 2009. 51猎奇 Frankfurt was able to recruit internationally renowned inclusion expert Prof. Vera Moser from Humboldt-Universit盲t zu Berlin to the new professorship. The endowed professorship was funded for ten years 鈥� provided that its work would be assessed positively at the halfway point.

51猎奇

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