Prof. Dr. Sebastian Ulrich
Where Good Questions Matter More Than Quick Answers
Anyone who has ever retrieved a forgotten lunchbox from a child’s school bag after the summer holidays—and found the courage to open it—knows one thing: mold is a remarkably resilient form of life. And anyone who takes a closer look before rushing to throw it away will discover something else: it can also be strangely fascinating—and even beautiful.
The World of Applied Microbiology
When Professor Dr. Sebastian Ulrich looks at a moldy lunchbox, he sees far more than spoiled food, but the fascinating interplay of microorganisms, metabolic processes, and biological interactions. For the head of the Applied Microbiology and Hygiene division at TH OWL, molds (explanation) and other microorganisms are the key to understanding biological processes—and the starting point for a wide range of research projects.
Microorganisms are everywhere. They live on our skin, in our food, in buildings, and in technical systems. Most of the time, we only notice them when they cause problems—when food spoils, mold appears in our homes, or they make us ill. Professor Ulrich, however, sees them as complex living organisms whose unique properties can help us better understand disease, improve food safety, and even develop sustainable materials for the future.
“Microbiology (explanation) is a highly interdisciplinary field,” says the professor, who completed his habilitation in bacteriology and mycology after qualifying as a veterinarian. “It connects with countless other fields—that’s what makes it so versatile and exciting.”
This diversity is reflected in the work of his research group. Their research spans food safety, medical hygiene, industrial microbiology, and biotechnology. Despite this broad spectrum, all projects share a common goal: to better understand microorganisms in order to develop solutions that benefit both society and industry.
The group brings together research staff, doctoral researchers, technical staff, and students. Professor Ulrich sees it as a learning community in which early-career researchers are encouraged to take responsibility from the very beginning and pursue their own ideas. Experienced scientists mentor the next generation, while doctoral researchers support one another—not only in their scientific work but also in navigating the many practical challenges of day-to-day research. Supported by TH OWL's modern laboratory facilities, this creates a research culture in which curiosity, openness, and mutual support are valued just as highly as scientific excellence.
Science as Detective Work
Time and again, companies turn to Professor Dr. Sebastian Ulrich's team when conventional laboratories can no longer provide clear answers. A food product suddenly begins to spoil, even though all quality control tests are normal. A product that has performed reliably in Europe for years behaves unexpectedly after being introduced to an Asian market. Or microorganisms survive even intensive cleaning procedures and permanently colonize industrial equipment.
“We often start where other laboratories stop,” Ulrich says. While accredited laboratories follow standardized testing protocols, his team has the freedom to explore new approaches.
Why did this particular microorganism become dominant? What conditions give it a competitive advantage? Which characteristics make it so resilient? For Ulrich, every one of these questions is a puzzle waiting to be solved—and an invitation to look beyond conventional approaches.
To answer them, his team develops specialized culture media, adapts cultivation conditions, and combines established analytical methods in new ways. They also use a MALDI Biotyper, a state-of-the-art instrument available at only two universities in Germany. It enables MALDI-TOF mass spectrometry (explanation), allowing microorganisms to be identified within minutes.
The answers do more than solve immediate practical problems. They also deepen our understanding of how microorganisms live, interact with one another, and adapt to their environment. It is precisely this combination of scientific curiosity and practical application that defines Sebastian Ulrich's research.
The Underestimated World of Molds
For many years, Sebastian Ulrich has been primarily interested in molds. What many people see as a sign of spoiled food or damp walls opens up a highly complex biological world to him.
One type of mold that particularly interests him is Stachybotrys chartarum. Certain species of this genus produce highly potent mycotoxins (explanation)—toxic secondary metabolites that can pose health risks to humans and animals.
In a project funded by the German Research Foundation, Ulrich and his team are investigating which genes (explanation) and proteins (explanation) are involved in the formation of these toxic metabolites and how their biosynthesis process (explanation) works in detail. Doctoral researcher Meyyappan Meyyappan is currently working on his dissertation in the field of fungal biology:
Fundamental Research on a Little-Studied Mold
"Stachybotrys chartarum is an interesting fungus. Very few research groups worldwide are studying this organism,” says doctoral researcher Meyyappan Meyyappan. The mold is found primarily in damp buildings and on organic material, where it can produce toxins that are highly harmful to human health. The aim of his research is to characterize the genes and proteins involved in the production of so-called macrocyclic trichothecenes (explanation), a group of particularly potent mycotoxins.
To achieve this, Meyyappan first investigates which genes are involved in toxin production and where the corresponding proteins are located within the cell after they are produced. Using molecular biology techniques, microscopy, and advanced analytical methods such as mass spectrometry, he aims to gradually unravel how the fungus synthesizes these complex metabolites. For genetic modificiations CRISPR-based methods (explanation) will be used in his research. They make it possible to selectively switch off or modify individual genes in order to clearly demonstrate their role in toxin production. The resulting mutant strains can then be compared with the original fungus.
Through his doctoral research, Meyyappan is making an important contribution to basic research. A better understanding of these metabolic processes could help improve health risk assessments and enable the development of new detection methods in the future with this fungus. At the same time, the findings and the genetic toolbox created for this organism may also open up long-term opportunities for biotechnological and pharmaceutical applications. Some of the natural compounds produced by this fungus are already being investigated for their potential as new therapeutic agents, including in cancer research.
From Discovery to Application
For Professor Dr. Sebastian Ulrich, basic research and practical application are inseparable. Some projects begin with a scientific question, while others are driven by a specific challenge from industry or society. What they all share is the same goal: to understand microorganisms well enough that this knowledge can lead to new solutions.
The work of his research group illustrates just how diverse these paths can be. While Meyyappan Meyyappan is deciphering the biological mechanisms of a little-studied fungus, doctoral researcher Justin Debrassine is applying microbiological knowledge to develop sustainable protein sources for the food industry.
Applied research that directly contributes to the startup
His doctoral research focuses on how different carbon and nitrogen sources influence the growth, biomass production, and protein content of the fungus Cladosporium herbarum. The aim is to identify the optimal cultivation conditions and thus establish the foundation for the efficient production of high-quality fungal protein.
“My goal is to understand the fungus and optimize its growth: I want to find out what the fungus needs to grow. Then, I want to produce as much biomass as possible with a high protein content in the shortest possible time,” explains doctoral researcher Justin Debrassine, who holds a master’s degree in Processing in Life Sciences.
He needs this knowledge for another project: His doctoral research is closely linked to the startup project PureSpore, which is funded through Start-up Transfer.NRW under the leadership of Prof. Dr. Sebastian Ulrich. Together with Florian Rempel, Debrassine is working toward the goal of using fermentation to convert previously unused byproducts from agriculture and the food industry into high-quality protein components. In the future, this could enable the production of sustainable, vegan, and low-allergen proteins that require significantly less water, land, and CO₂ than animal-based protein sources.
To identify the optimal growth conditions for the fungus, Debrassine uses a statistical experimental design approach (Design of Experiments, DOE). This method makes it possible to analyze multiple influencing factors simultaneously without having to conduct hundreds of individual experiments. It saves time and resources while providing reliable insights for future industrial applications.
For Debrassine, his doctoral research is much more than a scientific project. Together with Florian Rempel, he is working to translate the research findings into practical applications and transform the results into a viable startup.
A Culture of Collaborative Research
Although Justin Debrassine and Meyyappan Meyyappan work on different research topics, neither sees themselves as a lone researcher. On the contrary: Regular collaboration within the research group is an integral part of their work. While Meyyappan contributes his expertise in fundamental microbiological research, Debrassine approaches many research questions from the perspective of future industrial applications. Both benefit from these different perspectives—not only professionally but also personally. For Meyyappan in particular, who came to Germany to pursue his Ph.D., the support he received from the team when he joined TH OWL was especially important.
For Professor Dr. Sebastian Ulrich, this kind of collaboration is an essential part of successful research. Once a month, the three meet to discuss results, openly address challenges, and define new milestones. In between these meetings, the researchers work independently on their respective projects. “You need time to immerse yourself deeply in a topic,” says Ulrich. At the same time, he emphasizes the importance of regularly taking a step back, reflecting on one’s own progress, and gaining new inspiration through exchange with the team.
Making Research Accessible
For Professor Dr. Sebastian Ulrich, research does not end with a scientific publication. What matters to him is that new findings reach the people who can benefit from them in their everyday lives. “Many people perceive microorganisms as a threat. But,” says Ulrich, “they are also a resource.” His goal is to promote a rational understanding of the invisible world of microorganisms—one that is neither shaped by fear nor by carelessness. Above all, this requires clear and accessible science communication.
Through his direct interactions with the public, he repeatedly sees how great the need for information is. Many people encounter microorganisms every day but know little about their actual significance. Even basic knowledge can help reduce food waste, better assess health risks, and apply hygiene measures appropriately.
His favorite examples from everyday life illustrate this well: Mold on a piece of Parmesan does not automatically mean that the entire cheese has to be discarded—often, it is sufficient to generously remove the affected area. With jam, however, harmful mycotoxins may already have spread throughout the entire jar due to its high water content, even if the mold is visible in only one spot. The same applies to the “best-before” date, which is often misunderstood: It is not an expiration date, but rather a manufacturer’s guarantee of quality. It is therefore often worthwhile to trust your own senses—by looking, smelling, and tasting.
The COVID-19 pandemic also demonstrated to him how important a sound understanding of microbiological relationships is. His observation: While some people disinfected almost everything, others underestimated the actual risk of infection. From a microbiological perspective, both extremes are problematic. The key is knowing when hygiene measures are necessary and when naturally occurring microorganisms—such as the skin’s microbiome (explanation)—play an important protective role.
This is why Ulrich is committed to engaging with the public beyond his research and teaching activities. At TH OWL’s public engagement venue “anno 1578” in downtown Lemgo, he explained at a public event how mold develops in homes, what health risks it can pose, and how mold growth—for example, after water damage—can be prevented through proper ventilation and preventive measures. For him, this transfer of knowledge is just as much a part of a university’s mission as research and teaching.
From Veterinarian to Professor of Microbiology
Sebastian Ulrich originally wanted to become a veterinarian, ideally specializing in horses. Growing up in Italy and influenced by his education at a European School, he developed an early interest in understanding why living organisms function the way they do. He studied veterinary medicine at Ludwig Maximilian University of Munich, initially focusing on clinical work with horses, but gradually becoming more interested in the connections between animal health, food, the environment, and humans.
During his doctoral research, he first investigated molds of the genus Stachybotrys chartarum—a topic that continues to fascinate him today: How do mycotoxins develop? Which mechanisms are involved? And how can this knowledge be applied? This was followed by further training as a specialist veterinarian in meat hygiene and his habilitation.
In 2024, Ulrich joined TH OWL. A decisive factor was the close integration of research, teaching, and practical application offered by a university of applied sciences: Research questions often emerge directly from collaborations with companies, clinics, or public institutions, and interdisciplinary cooperation is part of everyday academic life.
Since then, he has headed the Applied Microbiology and Hygiene division within the Department of Agriculture, Food, and Health and has been a member of the Institute for Life Science Technologies (ILT.NRW) at TH OWL.
In addition to his research activities, teaching is another important part of his work. As dean of academic affairs, he contributes to the development of degree programs. Through his PROFuture-funded focus professorship on “Teaching for the Future,” he is also committed to developing innovative teaching and learning concepts.
PROFuture@TH-OWL is part of the BMFTR funding line “FH Personal” and is supported by funds from the Federal Ministry of Research, Technology, and Space (BMFTR) and the Joint Science Conference (GWK).
“Science thrives on staying open-minded and seeking to understand before passing judgment”
In this interview, Professor Dr. Sebastian Ulrich talks about his personal motivation, what he hopes to inspire in his students, and why he likes bringing grasshoppers to work.
Anyone who speaks with you often hears you say, “Don’t immediately say, ‘That won’t work.’” Why is this attitude so important to you?
Many good ideas seem unusual at first glance—sometimes even unrealistic. Students come to me with new approaches, colleagues from other disciplines contribute different perspectives, and companies face challenges for which there is no standard solution yet. If you dismiss such ideas right away, you miss the opportunity to explore new research questions and create genuine innovation. Science thrives on staying open-minded and seeking to understand before passing judgment. In situations like these, I consciously try to take a step back and look at the issue from different perspectives.
How do you ensure that young researchers take on responsibility at an early stage?
By placing my trust in them. Of course, I provide guidance, and we discuss their work regularly. But I want them to make their own decisions, shape their projects independently, and take responsibility for their research. Science thrives when people develop their own ideas. My role is to create the right conditions for that. And the same applies to them: stay curious. It is important to me that they learn from the very beginning not to be too quick to say, “That won’t work.” I want them to understand that the most exciting insights often emerge when people are willing to ask questions, bring together different perspectives, and work collaboratively to find solutions.
You are involved as Dean of Academic Affairs and through the “Future of Teaching” focus professorship. What advice would you like to give students as they move forward?
It is important to me that students learn to think scientifically. Subject expertise is the foundation, but curiosity, initiative, and the ability to critically reflect on connections are equally important. For me, good teaching means involving students in research as early as possible and giving them the opportunity to gain their own experience. In advanced courses, I like to introduce specific research questions from our projects and work with students to understand the challenges and explore possible solutions. It is incredibly rewarding to see how their methodological skills, subject knowledge, and ability to connect different aspects develop through these real-world applications. Many of them rediscover a whole new enthusiasm for microbiology along the way.
Next to your desk in your office is a terrarium with grasshoppers and frogs. What’s the story behind that?
They are always watching over my shoulder a little while I work at my desk. Sometimes they even seem to notice when I have forgotten a comma in an email. But seriously: I simply have a great passion for animals. I had my first stick insects as a child. Today, I keep and breed various species as a hobby and sometimes pass on many of the offspring to zoos, where they are used for environmental education. The frogs even had a scientific connection before I joined TH OWL, as they were part of neurotoxicity research conducted here at the time. In fact, it is difficult for me to completely separate my professional and personal life—my enthusiasm for biological processes is simply part of who I am.
We thank Professor Dr. Sebastian Ulrich for this fascinating insight into his work at TH OWL. Perhaps good research really does sometimes begin where others see nothing more than a moldy lunchbox.
Glossary
refers to the production of substances within a living cell. Researchers study these processes to understand, for example, how toxins are formed.
are molecular biology methods that can be used to specifically modify or deactivate individual genes. They enable researchers to investigate the function of specific genes in an organism—for example, whether a particular gene is involved in the production of fungal toxins.
is a segment of DNA that contains the instructions for producing a protein. Genes therefore determine many of an organism’s characteristics.
is a modern analytical method that can identify microorganisms based on their characteristic protein profiles within just a few minutes. It enables the rapid and precise identification of bacteria and fungi and is used in research, medicine, and food analysis.
are highly toxic metabolites produced by certain molds. They can damage cells and pose a health risk, which is why their formation and mode of action are the focus of intensive microbiological research.
is the study of microorganisms such as bacteria, fungi, and yeasts. It examines their characteristics, life cycles, and significance for health, the environment, and industry.
refers to the entire community of microorganisms that inhabit a specific environment, such as human skin or the gut. Many of these microorganisms perform important protective and metabolic functions.
are microscopic fungi that can grow on organic materials. Some are harmless or even beneficial, while others produce substances that can be harmful to health.
are toxic metabolites produced by certain molds. They can enter the body through contaminated food or other materials and may cause health problems.
perform almost all essential functions within a cell. They regulate metabolic processes, provide structural components, and transport substances.