BSE, bird flu, coronavirus: how the renowned virologist Thomas Mettenleiter has contributed to overcoming major epidemics, what has kept him on the Baltic Sea island of Riems for 27 years and what his audience can expect at the GDNÄ Assembly 2024.

Professor Mettenleiter, as President of the Friedrich Loeffler Institute, Federal Research Institute for Animal Health, for many years, you had to deal with world-shattering epidemics, just think of the BSE crisis, bird flu and the coronavirus pandemic. Which was the biggest challenge?
For me personally, it was definitely the BSE crisis. After that, nothing could scare me. I was still relatively new in office when the first cattle born and raised in Germany tested positive at the end of November 2000. The excitement was huge. At the time, we knew very little about the prions that caused the disease, but we were expected to provide competent information as soon as possible. Some time earlier, an informal expert commission had been set up under my chairmanship. In April 2000, we recommended that the Federal Government should prepare for the first case of indigenous BSE. Unfortunately, this did not happen. 

Nevertheless, the BSE crisis was ended quickly. How did this succeed?
The decisive factors were the ban imposed at EU level on the feeding of animal meal, for example, the removal of risk material from the food chain and the extensive testing of slaughtered cattle depending on their age. The number of cases then fell rapidly. As far as we know, only two animals born in March and May 2001 were still infected in Germany. It was an extremely turbulent time, during which two federal ministers, Andrea Fischer and Karl-Heinz Funke, resigned. During these years, I learnt how important communication between science, politics and the media is. Fortunately, the measures proposed by the scientific community were quickly implemented and proved successful. In this respect, the BSE crisis is a successful example of science-based disease control

© Friedrich-Loeffler-Institut

A scientist works in a full protective suit in the laboratory of the highest biosafety level 4 zoonoses. This is where research is conducted into pathogens such as Ebola and Nipah viruses. The suit is connected to the air supply via a valve, which constantly supplies air. This also inflates the suit so that even if there was a small hole, nothing would get inside via the escaping air flow. The scientist checks cell cultures on a screen.

How much was your expertise in demand during the coronavirus pandemic?
During the three COVID-19 years, other institutes were at the centre of political and media attention. However, we at the FLI were asked essential questions right at the beginning of the pandemic: Are farm animals in Germany susceptible to SARS-CoV-2? Does this jeopardise our food supply and do they represent a potential reservoir? Thanks to our modern research infrastructure on the island of Riems with high-security isolation stables, we were able to immediately test whether cattle, pigs and chickens, for example, are susceptible to the pathogen. We also investigated the interaction of the pathogen with other animals such as mice, golden hamsters, fruit bats, ferrets and raccoon dogs in order to find and characterise possible reservoirs or models for human infection.

What did you find out?
Cattle, pigs and chickens were not or only very slightly infectious and did not pass on the pathogen. In this respect, there was neither a risk in terms of food supply nor with regard to the creation of a new reservoir. Fruit bats, ferrets and raccoon dogs, on the other hand, proved to be susceptible to the pathogen, but did not fall ill and were still able to pass on the pathogen efficiently. This fits in with what we know about reservoir animals and bridge hosts. Hamsters and special genetically modified mice became severely ill. Ferrets, in particular, reproduced the largely mild human infection affecting only the upper respiratory tract, while golden hamsters and these mice showed the clinical picture of severe COVID-19.

There is currently much discussion about the need to come to terms with the coronavirus crisis. What do you think?
We should definitely analyse what happened objectively in order to learn from it for the future. Many decisions had to be made quickly and under uncertain conditions, especially during the hot phase – this should always be taken into account. A uniform policy for the whole country is important for the future; we should avoid a federal patchwork quilt in situations like this. However, the coronavirus years have also shown how immensely important basic research and modern research infrastructures are. We have them to thank for the highly effective mRNA vaccines, which had been researched for a long time, as well as numerous findings that helped us to survive the crisis. In order for this to continue in the future, sufficient funding is needed – not only for the establishment, but also for the maintenance of research facilities, personnel and training.

It is often said that the next pandemic is sure to come. What are the new threats?
We are currently in an inter-pandemic phase, that much is clear. But no one can say exactly where the dangers are coming from. What we do know is that three quarters of new human infections come from the animal kingdom and that pathogens such as the coronavirus continue to jump back and forth between animals and humans. We must never lose sight of influenza viruses: they are highly variable and adapt quickly to new circumstances. Fortunately, there is a global monitoring system for influenza viruses under the aegis of the World Health Organisation (WHO). We also need something similar to monitor animal populations in order to detect pandemic risks quickly. An international agreement on pandemic prevention, preparedness and response could help here. This is currently being negotiated under the leadership of the WHO and I am still cautiously optimistic that the member states will be able to agree on this. This would also be very much in line with the One Health concept, which is becoming increasingly popular and which sees humans as part of the animal kingdom in a shared environment.

The type of animal husbandry, which is also the focus of the Friedrich Loeffler Institute, plays an important role here. What trends do you see in this area?
The view is changing and animal welfare is becoming more important. In livestock farming, quality is becoming more important than quantity. To what extent and over what period of time this happens is also a question of funding and ultimately a political decision. This also applies to another issue: the silent pandemic of antibiotic resistance. It is favoured by the excessive use of antibiotics in all areas. In Germany, their use to promote growth in animal husbandry is banned, but this practice is still common in many countries. However, it is not just about animals; the use of antibiotics in humans must also be more targeted and more restrained.

© Friedrich-Loeffler-Institut

The Friedrich Loeffler Institute (FLI) has two animal barn units with biosafety level 4 zoonoses, where full protective suits are also mandatory. In Europe, only the FLI currently has such animal houses; there are a handful worldwide, for example in Canada and Australia.

You went to East Germany as a West German professor during the reunification period – and stayed there. What experiences did you have?
Initially, I was met with an interested distance, but also with curiosity and high expectations. The distance had to do with the fact that, unlike the institute directors before me, I am not a veterinarian, but a biologist. In addition, I was still quite young when I came to the island of Riems with my Tübingen working group in 1994. In the wake of reunification, the institutes had shrunk from 850 to 162 employees. The infrastructure was dilapidated. In my perhaps somewhat youthful recklessness, this did not deter me, but rather challenged me. What helped me a lot were the many motivated colleagues at all levels of the institute, who had a lot of expertise and experience. It has been a long journey, but today the Institute plays in the Champions League of the field, both academically and in terms of infrastructure. Its development is certainly one of the East German success stories, as described by my Greifswald colleagues Michael Hecker and Bärbel Friedrich in their book and in the interview on this website. For me, the Institute is a life’s work and I am happy to have been given the privilege of continuing the tradition of the co-discoverer of the virus, Friedrich Loeffler.

Your major research topic, animal viruses, has occupied you for a long time. How did you come across the topic?
The trigger was Hoimar v. Ditfurth’s history of evolution “In the beginning was hydrogen”. My parents gave me the book as a present in 1972 and I read it with great enthusiasm. I was particularly fascinated by an illustration depicting bacteriophages, i.e. viruses that infect bacteria. That was the seed for my career – and I am still an enthusiastic virologist.

That doesn’t sound like retirement, which you have officially been in for almost a year.
That’s right, I’m still very busy, even if I no longer spend up to 14 hours a week at the institute. But all in all, I have almost a full-time job again and sometimes I wonder how I used to do it on the side, so to speak. A new experience for me is giving talks to students about virology and One Health, for example last year in Göttingen and in the next few weeks in Greifswald and in Sigmaringen in Upper Swabia, my old home. I chair a working group on One Health at the Hamburg Academy of Sciences and Humanities and I chair the veterinary medicine section of the German National Academy of Sciences Leopoldina. As a scientific advisor, I support several UN organisations and the World Organisation for Animal Health in the One Health High-Level Expert Panel. I also continue to teach at universities and give lectures on my core topics.

At the GDNÄ Assembly 2024 in Potsdam, you will be giving a lecture on climate change and infectious diseases. Can you give us a few details?
I will be presenting the One Health concept in more detail, including its history, because it is by no means brand new. It will also be about pathogens, especially viruses, which are spreading as a result of climate change. We will be talking about so-called vectors, i.e. carriers of infections such as mosquitoes and ticks, which are influenced by climatic changes. The whole development has an uncanny dynamic and I try to visualise this.

Liane G. Benning, biogeochemist, on earthshaking interfaces, microbes in the Arctic ice and her El Dorado of research. 

Professor Benning, at the next meeting of the GDNÄ you will be giving a public evening lecture entitled “The big melt: small cells, big consequences”. Why should people make a note of this date?
I will be presenting new, previously little-known findings that are important for future climate forecasts. For example, it will be about snow and ice algae and their major influence on the melting of the Greenland ice sheet, which contributes significantly to global sea level rise. So anyone who is interested in current climate research and wants to know what we as scientists in Potsdam and Berlin are contributing to this is cordially invited to my lecture.

You head the Interface Geochemistry research group at the GFZ Helmholtz Centre Potsdam. What do interfaces have to do with the climate?
I need to expand a little on that. My research group is concerned with interfacial reactions. This refers to chemical, physical and biological reactions on and in the surfaces of a wide variety of materials that characterise their shape, structure and function. Our planet owes its appearance, both large and small, to such processes, which control the cycle of carbon, nutrients and trace elements. Climate change is also a consequence of interfacial reactions. One example is the reactions between carbon dioxide and the atmosphere. Another, more indirect example is the chain reactions in the Arctic ice.

© Katie Sipes

Field research that’s fun: GFZ doctoral student Rey Mourot collects snow and ice samples in southern Greenland. The helicopter in the background is standing by for safety reasons. The weather can change quickly, in which case the work has to be cancelled immediately. The photo was taken in May 2022.

How do you record the processes in interfaces?
We combine experimental approaches and measurements in nature, for example in Greenland, with satellite images, microbial sequencing and high-resolution electron microscopy and spectroscopy imaging techniques that we are constantly developing. In this way, we can observe interactions in interfaces down to the atomic level. The realisation that algae, viruses and bacteria play a key role in climate processes is thanks to this large repertoire of methods. 

Please explain in more detail how all this is connected.
Let’s take Greenland as an example. I’m there time and again with my team to take measurements on site and take ice samples, which we analyse when we return to Potsdam. The Greenland ice is still kilometres thick, but on average one metre melts away every year and goes into the oceans. This trend has been accelerating for years. This has to do not only with increasing global warming, but also with dark areas on the ice. They reduce the so-called albedo, i.e. the reflectivity of the surface, and heat it up. For a long time, it was thought that soot or dust particles blown onto the ice were blackening it. However, we now know that naturally occurring snow and ice algae, in combination with other microorganisms, play a significant role in the darkening – and are multiplying rapidly in Greenland. In the south-western part of the island, up to 26 per cent of the albedo reduction is due to ice algae. And as part of the major EU project “Deep Purple”, we are also investigating whether special viruses may control the algal bloom and how the bloom is slowed down by tiny fungi. 

Can such findings be used to slow down climate change?
What we are doing is purely basic research. We are not involved in measures to mitigate the effects of climate change. I also believe that bioengineering or geoengineering on the basis of previous research findings is premature because we still know far too little about the overall system. Individual interventions can cause great damage, so we have to be very careful. 

Is the new knowledge about algae and co. already being incorporated into climate forecasts?
In the last Intergovernmental Panel on Climate Change report from 2023, the contribution of algae was already mentioned, but bio-albedo is not yet included in the predictions. I am confident that the next assessment report will go into more detail about the effect.

© Katie Sipes

Liane G Benning and her doctoral student Rey Mourot in front of a snowfield in southern Greenland. You can clearly see how green, yellowish and red snow algae proliferate here.

You have been working in this specialised field for a long time. How did this come about?
I’ve actually always been fascinated by processes in the environment. I first studied mineralogy in Kiel and continued my studies at the ETH in Zurich, where I made geochemical reactions the subject of my doctorate. This was followed by academic posts in the USA and the UK, and over time I realised that I couldn’t make any scientific progress without biology. So I familiarised myself with the subject, especially genetics, and eventually I became a biogeochemist. 

You spent 17 years at the University of Leeds before moving to Potsdam and Berlin. How did you experience the change?
Coming back to Germany was a bit of a culture shock. In everyday life, I first had to get used to the rustic manners in Berlin and Brandenburg – things are a bit more polite in England. And then there’s the excessive bureaucracy with which the Germans torment themselves and others. The British – especially at universities – often work much more efficiently, so we can learn a lot from them. 

You’ve now been in the region for ten years and hopefully you’ve discovered some positive things.
A lot of positive things, in fact. Scientifically, I have fantastic opportunities here. If I need a modern, expensive measuring device for my research, I can almost always find it in the region –  be it at another Helmholtz Institute, at facilities of the Max Planck Society or at the Federal Institute for Materials Testing. And, just as importantly, my colleagues are highly competent, helpful and open to co-operation. For example, the collaboration with Thomas Leya from the Fraunhofer Institute for Cell Therapy and Immunology in Potsdam is brilliant. His biobank contains a wonderful snow algae culture that is ideal for comparisons with our ice algae. We were able to benefit greatly from the expertise of our Fraunhofer colleagues when setting up our culture. All in all, I couldn’t wish for a better environment for my research. 

Berlin-Brandenburg, an El Dorado for geoscientists?
I can agree with that. 

Then you probably have few problems attracting good young people to your team?
When we advertise a position, we receive applications from all over the world. That was the case again just now for a junior scientist position. But we didn’t find what we were looking for, the applications simply weren’t good enough. For some it was the incomplete documents, for others it was the narrow qualifications that were not sufficient for our interdisciplinary tasks. Some applicants just want to test their chances and are not serious. So it’s not that easy for us. 

How do you solve the problem?
In this specific case, we are now re-advertising the position with more precise criteria. I’m also sending the advert to colleagues I know around the world. Personal recommendations are very valuable. I also try to attract good young people from my degree programme at the FU Berlin to the GFZ: for an internship or for their final thesis. If it goes well, it can turn into a job. I also say this to the student interns from Potsdam who have been with us in recent years. My team has been great at dealing with their questions and requests and we are always happy to take on new interns from the region.

Marion Merklein, engineering scientist, company director and member of the GDNÄ Board, on turning points in mechanical engineering, taster courses and early successes with the hammer drill. 

Professor Merklein, at your institute at the University of Erlangen-Nuremberg, you develop entire production lines and realise them together with industrial companies. Are the prospects for German mechanical engineering really as bleak as is often said at the moment?
I’m not one of the pessimists. But there will be a lot of rumbling in the country over the next few years. Mechanical engineering is in the midst of a major transformation that will probably keep us busy until the end of the decade. Only then will things start to pick up again. 

What transformation are we dealing with in mechanical engineering?
The pivotal point is the energy transition, which will lead us away from fossil fuels and towards green electricity and hydrogen. At the same time, energy consumption and waste volumes are to be reduced. These alone are colossal challenges for the automotive industry and many other sectors of mechanical engineering. The situation is further exacerbated by the declining order situation against the backdrop of a global economic downturn and a dramatic shortage of skilled labour. We must not underestimate the problem from a social perspective, as one in five jobs in Germany depends on mechanical engineering. 

How does your research contribute to solving these problems?
At our university institute, a lot of research centres on the question of how to streamline process chains. For example, in the construction of hydrogen engines. Today, such engines are practically manufactory products with small series such as the °Mirai°: Toyota only produces 30,000 of these saloon cars with fuel cells per year. This is of course uneconomical in the long term. We are therefore currently designing production lines for large-scale production. The aim is to be able to produce millions of hydrogen drives for motor vehicles of all kinds in the future. We are also developing techniques to reduce heat consumption when joining components and chipless cutting techniques, which leads to less waste when cutting workpieces, for example. 

In addition to your work at the university, you are also the head of a company. What drives you?
We want to put research results from the university into practice faster than usual. That’s why I took over the management of the company “Neue Materialien Fürth” in 2019. This is a state research institution, 51 per cent of which is owned by the Free State of Bavaria and 49 per cent by several co-owners. I also own a share. The company can be compared to a Fraunhofer Institute, but with a much leaner administration. We have large industrial-scale facilities at our disposal. This enables us to carry out realistic experiments that are not possible at the university.

© FAU/Giulia Iannicelli

Are there already tangible results?
Yes, there are, and something will soon be added that will advance electrical engineering. It’s about an internal component that I can’t reveal any more about now because the patent process is still ongoing. The development is based on the results of a Transregio funding programme on sheet metal forming and is a good example of successful research transfer. Neue Materialien Fürth also carries out contract research and provides services – the bottom line is that we are in the black. 

Women are still a minority in mechanical engineering. What is the situation like in your environment?
When I took up my professorship, I was the only woman in the field far and wide. But a lot has happened over the years. Today, almost a third of professorships in mechanical engineering at FAU are held by women. I definitely see myself as a role model. And in my working groups, I realise time and again that mixed teams achieve the best results. 

Where does your fascination for the profession come from?
My father played a big role. I was eight years old when he put a Hilti in my hand to make a wall breakthrough. I really wanted to do it, he trusted me to do it and I managed it. I was very good at physics at school and when it came to studying, I decided in favour of materials science. As time went on, I liked mechanical engineering even better, I switched and did my doctorate in this subject.

© FAU

You quickly made a career for yourself and were already a professor at the age of 34. What gave you wings?
Above all, the reliable support of my doctoral supervisor and mentor, Professor Manfred Geiger. He encouraged me right from the start and took me along to all kinds of events and conferences. This allowed me to grow into management positions. 

Today, it is up to you to promote the next generation.
Unfortunately, young talent is rare. Compared to pre-pandemic times, we have up to 40 per cent fewer students and correspondingly fewer young academics. Technical science degree programmes have lost their appeal for young people. If they go in a technical direction at all, many of them tend to do vocational training. Foreign students can only partially compensate for this deficit. We therefore have to come up with something to get young people interested in our subject. 

What are you doing to achieve this?
My team and I give talks in schools, offer technology internships and, during the Whitsun holidays, we organise a taster university where students can look over our shoulders for a week. We are currently working on experiments suitable for small children, which we can also take to daycare centres. 

You are a representative for engineering sciences in the GDNÄ. What motivated you to take on this role?
I was asked very kindly by the Executive Board and considered the offer an honour. I like the interdisciplinary nature of the GDNÄ, that’s what makes it so special for me and I’m happy to get involved.