 Hey, guys. So thanks for the introduction. I am a PhD student in biophysics. And just like Rohit, I actually study molecular machines. But you are the experts in this topic now, so I don't need to talk about it anymore. Instead of me to talk about a project I was lucky enough to work with for the past year, which is cultured meat. So I was lucky enough to work with a group that was responsible for growing the world's first lab-grown hamburger. And I went to talk to you a little bit about this technology, cultured meat. So I'm excited about this tech because I'm really excited about food. And yeah, other people? Also excited about food? And as we heard from Natalia, food is a really important component of our sensory experience of the world. It's also a really important part of our culture. Our food culture is as tied to our identity as the languages that we speak and the ways that we think. But the way we produce food, specifically meat, is currently incredibly unsustainable. To give you an idea of what I mean, about 30% of our total landmass is currently dedicated to livestock production. So not just the livestock, but also the crops required to feed them. And 21% of our global freshwater resources go also to livestock production. And global climate change is only going to cause more and more pressure on these limited resources. And it turns out the livestock production actually exacerbates climate change. It's responsible for 18% of total greenhouse gas emissions. To give you a reference point, that's more than all the passenger cars, planes, and trains in the world combined, just from livestock. And if you think these problems are going to get any better with time, they're not, they're only gonna get worse. By 2050, we have an expected global population of about 9 billion and correspondingly about 150% increase in meat consumption, which we kind of expect because we're going to see individuals in developing nations obtain the wealth to purchase meat as time goes on. Another important thing to remember is that this is not what a farm looks like. We don't have any cows roaming around happy and empty pastures. We have most of our farmed animals in situations that look like this. On Earth right now, there are 70 billion farmed animals. And in addition to the concerns we might have for the way we treat these animals, it's also pretty bad for us because when you have all these animals together in close proximity, it's a high risk for disease and therefore over medication and therefore antibiotic resistance problems. So for all these reasons, the way we produce meat right now, it's a no-go for the future. So what can we do? Well, we could stop eating meat. So the average American, which I realize most of you here are not, consumes about 100 kilograms of beef per year. If that average American, which has removed the beef from their diet and replaced it with a nutritionally equivalent plant-based diet, they'll be responsible for 90% less crop consumption, crop land consumption rather, 35% less freshwater consumption, and 96% less equivalent CO2, so greenhouse gas emissions. So actually not eating meat solves a lot of our problems. So who's ready to go vegan? Yeah? Yeah? Everybody? No? Yeah, good. Okay. Well, it's okay if you don't raise your hand because as we talked about before, food is a really important part of our culture. Even if we rationally understand that maybe it's not the best idea to eat meat, it can be really difficult to sever the connections that we have to our favorite cheeses or our grandmother's goulash soup. So what really can we do while still maintaining our culture? So it seems like most of the problems associated with meat production don't really come from the meat. They mostly come from the animal. I mean, we've heard today animals are really huge, complex organisms. They have big brains, they have trillions and trillions of molecular machines running inside them all the time, complex metabolisms and organ systems, and all of these need energy, and animals have long lifespans, like the average cow before a slaughter is about three years old, so they need to be fed and nourished during all this time. But we don't actually need the rest of the animal. We don't need their big brains, we don't need their digestive systems, we only need their meat. That's kind of the idea behind cultured meat. Did you grow just the part of the animal that we're interested in eating, just the meat, in a laboratory without the animal? So some of you are probably thinking this is some crazy science fiction future, like, oh man, my food's gonna come from a laboratory, no way. But I'm actually here to tell you that this is a technology that is ongoing here now. So in 2013, this guy, Dr. Mark Post, he's my old boss, headed up a group at Maastricht University that produced the world's first left-grown hamburger, which you can see a little better here. And it looks pretty nice, right? So this was a proof of concept to show the world that we have the technology right now to forever change the way that we produce meat. And this project was a pretty big deal, it got a lot of media attention, had financial backing from Google's co-founder, Sergey Brin. So that was exciting, but the thing that was really exciting about this is that it sparked the whole field of cultured meat into existence. Since this first press release in 2013, about 30 companies have appeared in the world with the goal to make cultured meat come to market. And in addition to those companies, there are also dozens of research groups at universities and institutes that are also working on this technology. And since then, we've seen a lot of other actual, tasteable products that have been sort of revealed to the media. Everything from meatballs to foie gras or faux gras. We've seen sausages, we've seen chicken nuggets, we've even seen steak. So a quick little experiment right now. If you were in the room for any of these press releases, quick show of hands, who would be excited to try some of this cultured meat? Oh, a lot of you, good, 15 by four. But for those of you who don't have your hands up, that's totally fine. We're gonna talk about it. So welcome to the crash course on cultured meat. But before we talk about cultured meat, actually we need to talk about what we're trying to replicate. We're trying to replicate meat. So when we talk about meat, what we're typically referring to is skeletal muscle. So if you look at a piece of meat, you're typically gonna notice it's texture. It's kind of like stringy and fibrous. Those fibers are actually, that you can see with your naked eye, they're actually bundles of microscopic structures called myofibers. These myofibers are adult muscle cells that are fused together and to form these long fibers, which basically create the structure of meat. And this is the sort of structure of muscle in all organisms that have muscle. So our muscles look like this, my muscles, your muscles, the cow's muscles. And a really important cell type that exists within these bundles is called a myosatellite cell. So myosatellite cells are not exactly the same thing as muscle, but they have the potential to be. They basically spend most of their lifetimes hanging out on the outside of these myofibers. And then when the myofiber is stressed out or is damaged, for example, when you exercise, then these myosatellite cells, they wake up from their dormant state and they grow up and they mature into adult muscle cells, which can then fuse to join the rest of the myofiber. So this is kind of like the principle behind like why you see muscle mass increase when you work out. Basically you're damaging the old muscle and triggering these myosatellite cells to wake up and contribute to new muscle. So this process goes on in all muscles that are being used. And these myosatellite cells are replicative. So they're going to be the building blocks of our cultured meat. So how do we actually make it? So cultured meat production is, can be broken up into three steps. The first step is isolation of these myosatellite cells from an animal. So it starts with a pretty small sample of muscle from an animal from which you can physically remove the myosatellite cells and then put them into culture conditions. What this means is we try to trick these cells into thinking that they have never left the body. So we give them all the nutrients, amino acids, sugars, growth factors that they need to be well fed and happy. We keep them warm, 37 degrees, same temperature as a cow. Really make them think that they're in their natural environment. And this stage is called the proliferation stage because if we do everything correctly, after a day, one cell becomes two, after another day, two becomes four, four becomes eight. You see where I'm going with this. And after about 10 days, thanks to the power of exponential growth, you can see about a thousand-fold increase in cell mass. And this is the pretty crazy and exciting part about culture of meat because in theory, you can produce enough meat to feed the whole world from just a single cell. But remember, these are satellite cells. They're not exactly muscle yet. They're not recognizable as meat. So the same way that these cells can be triggered in your body to mature and to muscle, they can also be tricked or triggered in the culture environment to mature and to muscle. So we basically stress them out, change the media that they live in, decrease the amount of nutrients they receive, and they will sort of spontaneously start to grow up into these mature muscle cells, which, after two to four weeks, will fuse together to form the myofibers that we recognize from meat and muscle. And this whole process takes place without any genetic intervention. It's not a GMO. There's no genetic engineering involved. It's just cells doing what they would normally do in a body, because they think that they're in a body. Nice little, they fuse together. So this all sounds pretty great for this guy, right? It's pretty happy. In a few weeks, we can go from a single cell to an edible muscle fiber. That's great. So it just takes a few weeks to make, right? Where can I buy it? Well, nothing is that easy, right? So there are some obstacles that we still have to overcome before this product is going to be widely available, and one that I think is pretty important and is kind of a large bottleneck for the field right now is the issue of scalability. So right now, our farms look a lot like this. Our farming is like an industrialized practice, and the thing is cultured meat is a technology that's really in its infancy. It hasn't had the 1,000-year history of farming that has led to the evolution of industrialized farming. It's just less than 10 years old. So everything in the field right now, for the most part, is at a research scale. So research scale, like, what does that really mean? Just to give you an idea, that first hamburger that I showed you earlier, this is like a fraction of the plastic ware that was required to produce that first hamburger. So all of these boxes have to be manually exchanged. Two guys came in every day for like 10 to 12 hours a day. They were working nonstop just to maintain the cells to create enough cells to produce three hamburger patties, which were then cooked and eaten on live TV in this first press release. So it's great for a proof of concept. It's possible for sure. But this is not how we're gonna be able to feed the world. So what can we do? Well, everything I've described to you is a biological process that we have a pretty good handle on. And luckily for us, there are a lot of tools available to industrialize biological processes. We interact with them a lot, actually. So beer, for example, beer fermentation. That's a biological process that takes place at an industrial scale in reactors that look a lot like this one. Another example is biologic drugs. So if you take insulin or know anybody who does, that drug comes from a bioreactor that looks like this. So I sort of want to exploit the same technology in order to industrialize cultured meat. At a very high level, it's basically the same process I described to you earlier. You feed the cells what they want to be fed, nutrients, amino acids, growth factors, sugars, and you add the cells with their medium into this reactor. And if the environment is good, if they feel good there, then they can multiply, proliferate, and differentiate into edible muscle. And it's sort of a more high throughput meat machine than the bench top. So as I said before, this is sort of a really big area of growth in the field and is the focus of a lot of research because it's a big hurdle to overcome. But people are working so that our farms no longer look like this. And maybe one day could look a little bit like this. Very clean, very sterile, no animals involved, no need for antibiotics, no need for concern about health and safety. So I'm describing to you that we could use bioreactors, right? But it's all very vague. Like, what kind of bioreactor? What kind of machines could we use? And it turns out that nobody really knows yet. There are a lot of potential designs. There are a lot of different options that people can use. But we can make some guesses about what sorts of bioreactors and machines would be the most prevalent. Some clever people, specifically Dr. Hannah Tomisto at Oxford, have done some life cycle assessments to compare the potential environmental impacts of industrialized cultured meat to current industrial farming. So in this study, she made a lot of assumptions about what industrialized cultured meat production could really look like and then compared it to four different land animals and their typical production. So on the left you see a big black bar which refers to beef production, which is the highest impact in all the categories surveyed in this study. So in terms of land use, beef uses the most, followed by sheep, then pork, then poultry. And then cultured meat comes in at less than 5% of the predicted land use of beef, which makes a lot of sense because this is a factory system, right? You can go vertical. Your footprint doesn't have to be so big. You can't go vertical with pastures. In terms of water use, you all see a big decrease. This has a lot to do with the fact that we don't need to grow crops as extensively and at such a large scale as we need to grow to support actual animals. In terms of greenhouse gas emissions, you see a very similar trend. The only sort of category in which cultured meat doesn't really win out from a sustainability perspective is in terms of energy use because we're expecting this to be like a lot of really big machines working together. Drill require a lot of energy and it might actually be a little bit worse for the environment than say, for example, poultry or comparable to pork production. But these are numbers that we're hoping will improve as our best guesses get better and as our technologies get more and more efficient. And ideally, the negative impact of increased energy use will go down with time as our energy infrastructure also becomes greener. So it's kind of a trade-off there. So based on the previous slide, you can kind of understand that cultured meat has the potential to solve a lot of the problems we already laid out. And everything I've described to you so far has been about trying to replicate meat exactly as we know it. But the thing that's really cool and exciting about cultured meat is that it offers us a lot of control in the way we produce our food, like unprecedented control because we're sitting in the driver's seat from the very beginning from when we first get that first sell. So we can imagine crazy possibilities for what our food production could look like based on this technology. For example, we can control the protein or the fat content of our meat. We can make the highest quality product possible. Everybody gets to eat Kobe steak all the time. We can also change the nutritional content of our meat. We can select for good fats that are not typically present in animals and increase the ratio to bad fats. We can supplement our meat with nutrients, vitamins, and minerals that might be deficient in our diet the same way most of our salt is now fortified with iodide. And you can even go a step further actually and you can think of a world in which you can use meat, like your food, as a delivery vehicle for your medicine. And it also gets wacky because currently our food production or our food culture is based on whatever animals were easy to catch or domesticate for our ancestors. We never optimized for tastiness. But what if there are some animals out there that are incredibly tasty? What about extinct animals? Like does a dinosaur leg taste good? Only one way to find out. Is this some exciting office we can think of? And as was mentioned before, a little bit excited about space. So if you want to go to Mars or you wanna go on any long distance interstellar trip, you're gonna need to feed the people that go on that. Nobody's planning to bring a cow or a sheep or a chicken on board. I mean, maybe, but not a great idea, right? But you can conceivably bring a bioreactor on board and have a nice like caloric source right on board with you. So I guess the point I'm trying to make here is if we can accept cultured meat as an option for us, the sort of the sky's the limit in terms of what we can imagine for its future potential. So quick summary, cultured meat is an emerging technology that has the potential to solve a lot of the problems that are inherent in our current meat production system. And it can even do better. So when can we expect it? All these technological questions that I've laid out in this presentation so far, so primarily about scalability, but also about optimizing the biological process, these are technological considerations that probably can be solved within the next 10 years. So people estimate that within the next 10 years, you should be able to see these products on your supermarket shelves, hopefully at a competitive price point that you can eventually produce meat. Some estimates are even earlier, but I would be skeptical. But the whole point is when those products arrive, none of the positive benefits that you get from them are going to matter if people don't buy this stuff. In order to really access these improved parameters, you really need to see a big shift of consumer acceptance basically from conventional meat to this new thing. And this can be tough, right? Because this is a potentially very disruptive technology, like our intuition doesn't really explain how this works. We can intuitively understand where our meat comes from now, but the average person doesn't really maybe intuitively get how this whole lab-grown meat thing works. So this is sort of where you guys, and 15 by four and scientific communication in general comes in, because we sort of want to foster a society in which people are open to trying new things, trying new technologies that might alleviate the problems inherent in our current system. So I asked you guys before, and now we have a little bit more information. Maybe the results will change. Who here would be interested in trying cultured meat? I'm gonna feed my ego and say that more if you put your hands up this time. That's great. And I guess the point I would like to make is that this is something that's coming and it's really important for us to be talking about it early, to be thinking about early, to be educating ourselves and always sort of understanding the problems inherent in the system, why we need this, where it currently is and where it's going. Thanks a lot, guys. Thank you very much, Fri. I see there's already questions already here. Could you please bring us the microphone in the second row and close to the middle? Thank you. I would like to, you already mentioned that we can somehow fine tune the content and the nutrition of the meat, but can you grow like a sirloin steak and flank steak and so on, T-bone and all those different kinds of the meat? The question is, could you grow different kinds of the meat, maybe elaborate a bit on how it can be done? Yeah, definitely. So basically what you're asking is different cuts of meat, which taste and feel different to us. And that's typically a mixture of different properties. It's different types of fats and different sort of densities and types of muscle. And we have a pretty good understanding, so meat science is a crazy huge field and they have a pretty good understanding of what makes certain meats more desirable than others, what traits define sirloin steak versus flank steak, for example. And it's primarily about different ratios of different cell types. So I think it's a relatively easy problem to solve to figure out which cut of meat you want to replicate. Thank you. There is a question also here in front row. Yes, coming here, very good. Let's say that we have normal meat as we know it and we have cultured meat. Is it easy to distinguish and say, this is cultured, this is normal meat if we have them both together? Okay, this is the question we rehearsed. Yeah, the question is, can the person distinguish the normal or regular traditional meat from the cultured meat? So, I mean, in theory, I mean, the idea is no. The idea is that we want to replicate really everything about meats that we know and understand in the cultured meat product. How it actually plays out, at least currently, is maybe a little bit different. So for example, right now, it's really difficult for us to grow whole pieces of tissue. This is like an ongoing problem in biology. Like how do you grow a huge piece of tissue? So for a while at least, if somebody tries to give you a whole steak and say it gets cultured, you can probably kind of safely guess that it's not only the case. But in general, I think the idea is that it's supposed to be indistinguishable. Thank you. There is a question there. Please, whoever you choose now is a lucky person. I have a very short question. So you need some nutrients, some crow factors to grow the cells and can you all grow them in an animal-free environment? Or do you need to kill animals to get to Syria and then feed the cells of that? The question is, do you still need to kill animals to get some of the components that you feed to the cells to grow them for cultured meat? Yeah, this is a really good question because actually the current answer to that question is mostly yes. So in almost all cell culture, for animals and humans as well, we use ingredients that come from the blood serum of animals. Typically, it's called fetal bovine serum. It's usually coming from like a young cow. And this is something that needs to be removed from the process entirely before this product can come to market because it still relies a lot on animals then which is something we're trying to avoid entirely. So there's a lot of research in the field sort of trying to get away from this. So various companies and research groups have claims that they can grow their cells in animal-free environments. What that means is that they have to sort of really like closely evaluate what a cell actually needs and give exactly all those components to that cell. And so for some cell types, we just know them better. They've been around longer, we've been studying them longer, so it's much easier to generate like a serum-free media for those cells. And for other ones, for example, some types of cow or fish that we don't typically have in like a research environment. We don't know that much about them so it's much more difficult to specifically tailor to their nutritional needs. So long answer, yes, but we're trying to move away from the reliance on animal products. Thank you. I think now we need to move on, but I saw there are more questions. Please ask Freya after the talk. She is staying around for a while and you can ask more about culture media where to get it. Thank you very much. Thanks, guys. Thank you.