“Clean” Meat from the Lab

Researchers at Reutlingen University keep a close eye on animal welfare and environmental protection

Enjoying the taste of meat without killing animals – a research challenge that is more topical than ever. Shocking images from factory farming, scandals in the meat industry, and the dramatic impacts of meat production on the climate require solutions that are not just sustainable, but will also stand the test of time. Prof. Dr. Petra Kluger, Vice President of Research at Reutlingen University, has taken up this challenge and is working in the laboratory to cultivate artificial meat from isolated animal cells. Her research focuses on two key questions: How to succeed with mass production, and what healthy meat might be like if it is produced artificially. Kluger recently reported on her findings to date as an expert at the #techourfuture series of events on The Future of Nutrition.

This slideshow requires JavaScript.

It all began when Petra Kluger was running lectures on “tissue engineering” – the practice of cultivating tissues. This inevitably led to the topic of meat from the lab. In fact there was such strong interest in the topic, not only among students but also at her opening talk at the International Conference on Cultured Meat in Maastricht in 2018, that the graduate of biology decided to start researching the topic herself. Before beginning to cultivating meat in the lab in 2019, she had already been involved in cultivating human tissue for biomedical purposes at Reutlingen University. Meanwhile, the research group under Petra Kluger, which comprises doctoral candidates, scientists, and students, is working on a number of research projects.

To obtain the stem cells they need to cultivate meat in the lab, the researchers only require a small piece of pork or beef, so no animals are slaughtered specifically for research purposes. The meat is digested using enzymes before being passed through sieves to separate the smaller stem cells from larger constituents. The lab in Reutlingen takes the cells that have been isolated in this way and breeds them at 37 degrees Celsius in an incubator. The cells are then fed into a 3D printer, where they are constructed into an edible piece of meat – complete with muscle and fat tissue that can basically be formed into any shape.

Kluger is passionate about the potential offered by her research: “Compared to conventional meat production, meat from the lab is much less resource-intensive in terms of water and farming land, and it produces fewer greenhouse gases. “As a result, it offers a sustainable alternative to meat supplied along the lines that have been common until now. This kind of ‘clean meat’ – the term now used in English – is also good for animal welfare, and it poses fewer of the health risks associated with conventional meat production, particularly those caused by using antibiotics in factory farming.”

The Reutlingen-based research group is currently working on preparing the 3D printer meat for commercialization. One of the key issues of mass production is costs. In May 2020, Reutlingen University and the University of Hohenheim launched a joint project with funding from the Avina Foundation aimed at developing solutions for scaling up production methods to industrial volumes. “We’re looking into ways to advance production on an industrial scale. To do this, we’re optimizing manufacturing processes to ensure we have enough cells for large production volumes,” explains Kluger.

Another approach being looked at is how to produce healthy meat in the laboratory. The idea is to supplement artificial meat with nutrients such as folic acid for pregnant women, vitamins, or nutrients to help promote muscle gain. The research team from Reutlingen is looking into ways to combine lab meat with food supplements to offer healthy alternatives to meat and thus address consumer skepticism. The reason for this is that there is still low acceptance among the general public for “designer meat.”

It will probably not be possible to exactly replicate animal meat by using lab meat in the near future, but Kluger does not consider this an absolute necessity. Instead, the researchers from Reutlingen can imagine their work leading to completely new products as an alternative to conventional meat. Bottom line, Kulger believes it will not be possible to stem the tide moving toward meat alternatives due to social changes and the need to protect the climate, human health, and animals – as well as the need to secure food supplies for the Earth’s population in the long term.

“Ultimately, it’s the consumer who decides”

An interview with Professor Dr. Petra Kluger, Vice President of Research at the University of Reutlingen

Hello Professor Kluger. You’re working on the production of artificial meat. What advantages does artificial meat offer compared to meat from conventional production?

With conventional production, large areas of land, high volumes of water, and a lot of energy are used even before animals are ready for slaughter. This also produces high volumes of greenhouse gases that cause damage to the environment. All of this can be significantly reduced by producing meat in the laboratory. And as more and more people now live on this planet, it simply won’t be possible to feed everyone with meat produced through conventional methods. The alternative, which we’d like to play a part in setting up, is highly interesting if you want to protect the environment and at the same time provide humankind with protein-rich food.

How well do you think meat from a 3D printer would be accepted among the population, and what reservations do people have?

People have a large number of reservations, although this has decreased significantly in recent years. For example five years ago, people thought you were crazy if you started talking about artificial meat. In the meantime, there’s been a shift in society. This can also be seen in vegetarian products, which are now also much more widely accepted than they were just a handful of years ago. When you mention artificial meat, some people ask what the benefits are or why it makes sense, because you could just become a vegetarian instead. Of course that would actually be the most climate-friendly option, but although we know from the figures that the proportion of vegetarians is gradually rising, it’s still a relatively low number. Other skeptics claim that our product is not real meat, but something artificial instead, so they also ask what the benefit is supposed to be. Our answer to both groups is that no-one’s forcing you to eat it. It’s simply another alternative source of nutrition.

There are lots of reports at the moment on how livestock is kept and the slaughtering conditions of animals. These are not because people think cows should be grazing in lush, green meadows; they’re more to do with fattening farms where they use antibiotics, or with animal diseases that keep coming back again. Because the cells we use for 3D printing are currently sourced from small slaughterhouses, we’re investing a lot of time in looking into slaughtering methods. If I’m honest, the more you look into this topic the more you do start to wonder. One of the advantages we have when we’re cultivating meat in the lab is that the process takes place in a sterile environment, so ideally we don’t need to use antibiotics. Also, in the lab you don’t have diseases like swine fever, which is going around again at the moment. But ultimately, it’s the consumer who decides and there’ll be enough people who will continue to eat conventional meat. Maybe the trend will go toward more organic meat with this consumer group, because lower quantities of meat will be needed.

But one thing that should be noted at this point is that when it comes to producing meat in the lab, there are still lots and lots of ways to make improvements. The idea is that later down the line we’ll be able to take the cells we require from a cow so we can generate a kind of cell line. This is an area lots of my colleagues are working on, not just in the work I’m carrying out with my research team. We don’t yet have any such cell lines, so we’re using slaughterhouse waste that’s not used by butchers. Another starting point is to look at the medium the cells grow in. At the moment, it still contains lots of animal ingredients, so we’re trying to change that. This is necessary so we’re not dependent on conventional meat production again, but also to find cost-effective ways to go into mass production.

It’s not uncommon to encounter public resistance to new technology and industrial processes. What can be done about this, and how important do you think it is to keep the general public well informed?

It’s extremely important to keep people well informed. In fact this is one of the most fundamental aspects, because it’s one thing to develop a technology, but it’s acceptance among the population that determines whether a technology is put to use, or how it’s used. I think it’s crucial that new technology is thoroughly investigated in scientific terms, and that the results are published in such a way that the underlying science is understandable to the general public.

There’s actually not a lot going on in Germany at the moment when it comes to lab meat, but for example in the US, the Netherlands and Israel, there are already lots of firms and startups talking about launching such products in the near future. But if consumers don’t know enough about this topic, it won’t take long for fears to arise and even rejection. This is why it’s hugely important to ensure the research is kept transparent. I also think it’s important that there’s public funding for research in this area. We need a lot more know-how and a lot more facts, which will then also be made available to the general public – so consumers. And we need to explain the facts to consumers and discuss these with them so they can decide for themselves: Is this something I want, or not?

You’re currently working on transferring artificial meat from the lab into mass production. What do you think the biggest challenge will be with this?

I’ve already mentioned the first challenge, which is about having the required big volumes of cells. Another important issue is where the cells come from. Taking cells from the slaughterhouse is not really appropriate in the long run, but we will have a cell line. We’ll then allow the cells to float around in a nutrient solution. That said, this approach is still incredibly expensive because of the volume of animal ingredients you need, and it’s not really sustainable. The idea with mass production is that we want to be able to produce tons of meat, so we’ll need to find another option, one that works and is still relatively inexpensive. The methods used to cultivate meat are also important, because at the moment we’re still growing it in Petri dishes, i.e. plastic. These are then thrown away and this also wouldn’t be sustainable in mass production. The idea we’re looking into is to move to bioreactors, i.e. suspension culture, so cells no longer adhere to each other but float in a solution that can be as big as you want. In scientific terms, it will be extremely exciting to see if we can get this process to work with our cells, which actually do need something to adhere to instead of floating around in a solution.

If mass production does prove successful, do you think “clean” meat will completely replace conventional meat in the future, or will it just be an alternative?

I think that’s also just a question of time. Some consumers are sure to try the meat. As I said, we’re already seeing this happen with vegetarian products. Also, only a few years ago, hardly anyone would’ve imagined that you could buy insect snacks at a discount store. So changes are already happening right now, and that’s why I’m convinced there’ll be people who will try artificial meat immediately. But the number of users will only increase gradually and rise in line with the number of products available. Conventional meat production is sure to continue for many decades to come. But if it’s possible to eat products that are not just similar to meat but taste just as good, and if you don’t have to kill animals to enjoy them, I can imagine there will be a shift in society.

Not only that, but it’s not as if we want to replicate meat like for like; we also want to offer additional benefits and other nutritional alternatives – for example meat with folic acid for pregnant women or meat-algae products.


Prof. Dr. Petra Kluger (author)
Vice President of Research
Reutlingen University (Reutlingen)