High UV radiation, heavy metals, extreme temperature fluctuations, low oxygen levels: some microbes thrive in places it’s hard to even imagine. Geomicrobiologist Dr. Judith Klatt, who has been working at the Max Planck Institute for Terrestrial Microbiology in Marburg since 2022 and serves as a research group leader at the Mikrokosmos Erde Future Center, took her audience at the Steinmühle on research journeys to explore these microbial survival experts.

Interdisciplinary Work

The scientific lecture “Bacteria at the Limit” was also a journey back to the very first microbes and the origins of life: “It’s about understanding microbial life and, at the same time, the limits of life,” said Dr. Judith Klatt. This understanding emerges at the intersection of several disciplines: physics, biology, and chemistry.

A broad temporal scope

One of Dr. Klatt’s research sites, for example, is Hawaii: “Our work opens a window into Earth’s history spanning a timeline of 4.5 billion years,” the researcher reported, thereby giving her audience an idea of the temporal scale under consideration. Environmental science topics are also frequently incorporated into her research stays, helping to better understand the fluctuations in maximum temperature and in the oxygen and CO2 levels of the atmosphere throughout Earth’s history. According to Dr. Klatt, both are very closely linked to the “global microbiome.”

Fundamentals of Molecular Biology

Extreme habitats continually open up new horizons for research and research teams. For example, the fundamentals of molecular biology were isolated from microbes in extremely hot or cold habitats: these include the enzymes used in polymerase chain reactions (PCR), which form the basis for paternity tests and DNA fingerprinting in forensic science. Microorganisms such as cyanobacteria—commonly known as blue-green algae—have also been responsible for oxygen production and played a key role in the oxygenation of our atmosphere during the Precambrian era. Cyanobacteria are single-celled organisms that live in both fresh and saltwater and obtain their energy through photosynthesis, much like our green plants. This process produces oxygen, which escapes from the “microbial mats” and can be measured by Dr. Klatt’s team, for example, using microsensors.

Research Under the Most Challenging Conditions

“It can be difficult to work in the field,” the speaker recalled, citing, for example, a research trip to the high Andes at an altitude of 3,000 meters. A 24-hour trek to the nearest supermarket presented the research team not only with the challenge of answering their research question using complex methods but also with the difficult task of self-sufficiency. No stable life for microorganisms has been detected there so far. Oxygen alone, therefore, is not a reliable indicator of life.

Impressive photos

At the Max Planck Institute for Terrestrial Microbiology in Marburg, the extreme conditions that the research team encounters in the field are also simulated in the laboratory. “While we can never quite replicate the conditions from field research exactly as they occur in nature, this approach still allows us to study the enormous dynamics within an extreme habitat very realistically, even over longer periods of time,” explains Dr. Judith Klatt, who illustrated her presentation with impressive photos and sparked great enthusiasm among the students with her talk.

Outstanding Researcher

Through her work, Dr. Judith Klatt helps make Marburg a center of excellence in cutting-edge research. In 2024, for example, she was awarded an ERC Starting Grant by the European Research Council.

The presentation was part of the “Microbes for Future” lecture series organized by the Max Planck Institute for Terrestrial Microbiology in Marburg in cooperation with the Central Hesse Student Research Center (SFZ).

The scientific presentations will continue.

(Angela Heinemann / Dr. Sven-A. Freibert)

Conveying complex topics in a way that is tailored to the audience—this is, at best, a skill possessed by professors, lecturers in general, and also by teachers. With this in mind, Björn Gemmer, principal of Steinmühle School, expressly praised the Marburg-based biologist and chemist Prof. Dr. Tobias Erb of the Max Planck Institute for Terrestrial Microbiology for his public lecture at Steinmühle.

About 100 interested attendees came to hear the presentation on the topic “Microbial Power—New Paths Out of the Climate Crisis.” In the auditorium were students from the advanced biology classes in grades Q2 and Q4, students from the introductory biology class in our Q4, as well as external attendees and all members of the plus-MINT group from Steinmühle.

How can microbiology help reduce the CO2 content of the atmosphere?

That was the topic of the lecture, which biology and math teacher Dr. Sven Freibert—a member of Steinmühle’s Plus-MINT support team—summarized as follows:

The “terrestrial microbiome” plays an enormously important role in the carbon cycle. The sequestration of CO2—including anthropogenic CO2—is carried out almost entirely by terrestrial plants and aquatic microorganisms. The latter are primarily found in the world’s oceans. However, the efficiency of CO₂ fixation by microorganisms is not very high. Due to the comparatively high availability of CO₂ throughout both the older and more recent geological history, there has been—and continues to be—no evolutionary pressure to significantly improve this efficiency.

Microbiology—or, more specifically in this case, synthetic microbiology—and, above all, the team led by Prof. Dr. Tobias Erb has now made this “problem” of efficiency the focus of its research. The goal is to use microbiological, genetic, and biochemical methods to identify and isolate metabolic pathways in microorganisms and increase their efficiency, with the ultimate aim of using these molecular machines for artificial CO₂ fixation. It should be noted, however, that the goal is not to release artificially produced microorganisms!

Another approach being pursued by Prof. Erb’s team is to genetically modify crops that are grown in large quantities so that these plants can fix CO2 more efficiently. This would have the dual advantage of removing large amounts of anthropogenic CO₂ from the atmosphere and enabling the plants to grow significantly faster, which in turn would make food much more readily available and thus contribute to global food security. “Killing two birds with one stone”!

The audience’s full attention

It’s not usually the case that an audience listens spellbound to a speaker from start to finish. Tobias Erb managed to hold the audience’s full attention throughout his nearly 45-minute presentation. He struck the right balance between technical expertise and clarity, and during the subsequent Q&A session—which lasted about 30 minutes—it became clear that he had truly engaged the audience with his content.

In closing, Erb expressly praised the keen interest shown by the Steinmühlen students as well as the quality of their questions.

Speaker Sparked Interest in Research

Professor Erb began by introducing the Max Planck Institute in Marburg as one of a total of 86 Max Planck Institutes. He highlighted the quality of the research, which is evident not least in the numerous awards, including several Nobel Prizes. The scientist highlighted the work of the international research teams and sparked an interest in scientific research.

Central Hesse Student Research Center as the organizer

In closing, Steinmühlen School Principal Björn Gemmer thanked not only the speaker, Prof. Dr. Tobias Erb, and Dr. Virginia Geisel, the press officer, but also the Central Hesse Student Research Center, which initiated and organized the event. As part of this group, Steinmühle is hosting four lectures in the “Microbes@School” lecture series.

(Gem / Dr. S. Freib / Heinm)