How to “Grow” Animal Products: An Introduction to Cellular Agriculture
Picture a farm.
If you’re like me, then you probably see something like this.
Lone farmers in overalls tending to grassy embankments of golden hay. Cows lazily swatting flies with their tails and children playfully collecting milk in a crisp and dewy sunrise. A weathered couple gazing out over a vast expanse of jeweled crop rows while a fiddle plays somewhere in the distance.
It’s bucolic, homey… and honestly, mostly false.
The majority of farms look a lot less like our pastoral day dreams and a lot more like this.
A factory.
In this situation, a chicken is born one day into a cramped metal shed with 35,000 others of its kind. It will never go outside, breathe fresh air or do any of the other things we inherently believe chickens have the luxury of doing. A chicken here will walk around in its own waste until 35 days later, it’s taken to a processing plant and gassed to death, chopped into 9 pieces and sent out for processing where it’ll become part of someone’s chicken nuggets, chicken burger or something else of the kind.
How can we let something this inhumane go on?
Our food system is almost by definition cruel, wasteful and disturbing — but we are able to explain these things away when presented with something like, say, a medium rare steak. You might contemplate vegetarianism, but as soon as you take the first bite of that juicy, smoky cut of meat, such resolutions go down the drain. It just tastes too darn good.
So, how can we have the steak with out the animal cruelty, the environmental waste and food insecurity that it currently entails? Cellular agriculture just might be the trick.
What is Cellular Agriculture?
Cellular agriculture is the science of creating animal products without raising animals. There are two main kinds of cellular agriculture: “cellular agriculture” which is concerned with making products containing once living cells (like meat and leather)
and “acellular agriculture” which is about creating animal-derived products (like cheese and milk).
How does it work?
For now, we’re going to focus on cellular agriculture (that is, not acellular agriculture). When we produce meat using cellular agriculture, we are said to be “culturing it in vitro”. This is done in three main steps.
- Stem cells are extracted from the animal. Stem cells have the potential to become many or all of the different types of cells found in an animal which makes them ideal for creating the different parts of meat. In the case of a primary culture, adult stem cells are taken from the reserves of an animal’s specialized tissues — tissues that already have a specific purpose (like skin or muscle) — and are called progenitors. In the case of secondary cultures, cells might be cryopreserved (frozen) from previous experiments.
- Stem cells are immersed in a culture medium and proliferate. A culture medium is a substance containing everything cells need to grow like carbohydrates, fats, amino acids, salts and vitamins. As these molecules diffuse into the cells, they grow and eventually split into two smaller genetically identical cells. In this way, our population of stem cells increases exponentially, or “proliferates”.
- Stem cells are put into a bioreactor and differentiate. Bioreactors are machines that expose the cells to a variety of different environmental cues — for instance, electrical stimulation and mechanical contractions. This encourages the cells to differentiate into the types of specialized cells we get in meat (like muscle, fat… etc). These myoblasts then fuse to form multinucleated myofibers — i.e. tissue.
And bam, we have perfect steak…well, not quite.
This process would be just about where everything ends for unstructured meat, but not for structured meat. Unstructured meat is, as it sounds, meat that doesn’t have a real structure (like ground beef).
Structured meat, on the other hand, is meat that has a specific composition of cells — it’s not just the type of cells that characterize it, but the arrangement too (like steak).
Getting a particular arrangement is not reliable by just allowing the cells to float around in the bioreactor and crossing our fingers. So, we need something called a scaffold. A scaffold is a mold in which the cells grow in and around to form the specific shape and structure of the meat. The proliferated cells are usually seeded onto the scaffold (i.e. attached to it) and then put inside the bioreactor.
Some popular scaffolding materials include decellularized plant tissue, chitosan or recombinant collagen. Researchers at the University of Ottawa and University of Western Australia have been looking into the benefits and downsides of each type, and found the following:
Decellularized plant tissue is abundant and has a great structure and texture. However, it lacks many of the growth cues deemed vital for growing mammalian cells.
Chitosan is abundant and has antibacterial properties. It can also be blended easily with other polymers which suggests that it could easily be tailored to what a scientist is trying to grow. However, in the presence of lysozymes (a naturally occurring enzyme), chitosan will start to break down in unpredictable ways.
Recombinant collagen is highly biocompatible but is hard to produce and source.
All of these scaffold variations are favoured by researchers because of their commonality: they can be produced by plants or fungus, and are hence unreliant on animals.
So there, now we have our perfect steak. Well, again…there’s more.
We may have a nicely structured cut of meat, but now we have a scaffold in it. Scientists have proposed using edible scaffolds, but since the whole idea behind the cultured meat is to perfectly replicate meat, scientists are leaning towards figuring out a way to make biodegradable scaffolds. But this in itself introduces some new issues, most notably the rate of decay. If our scaffold literally disappears while the meat is growing on it, it kind of defeats the purpose.
So, why do we care about cellular agriculture?
In a nutshell, cellular agriculture has the potential to decrease the negative effects food production has on the environment. For instance, in a Life Cycle Assessment published by the American Chemical Society,
producing 1000 kg of meat conventionally is expected to require “26–33 GJ energy, 367–521 m³ water, 190–230 m² land, and emits 1900–2240 kg CO2-eq GHG emissions”.
On the other hand,
producing the same quantity of meat in vitro has “7–45% lower energy use… 78–96% lower GHG emissions, 99% lower land use, and 82–96% lower water use”
The difference between the resource consumption of these two methods is huge, but what allows this to be so? Let’s say you wanted to make a steak.
Traditionally, this requires you to raise the whole animal — the steak + all other parts of the cow (leather, bone, major organs, cartilage, blood…etc) + a life’s worth of essential processes.
Using cellular agriculture, you would only have to nurture the steak.
What’s more, cellular agriculture has massive implications for animal welfare. In order to remain competitive, large corporations will often sacrifice the health of their livestock to decrease their expenses. Cellular agriculture (by virtue of the fact it barely relies on animals, to begin with) sidesteps this problem. This is so convenient, that critics of the field caution that
“we should not trust in a technological fix because it will not solve our real problems; let us rather aim for changes in agricultural practices, our values and/or our behavior”.
This is a valid point — at the end of the day, it’s our human tendencies that engineer potentially detrimental situations. However, it remains indisputable that less livestock means less chances for livestock mismanagement.
What’s preventing cellular agriculture from becoming mainstream?
The main challenge this technology faces is the cost — the world’s first cultured burger which was produced by Dutch scientist Mark Post and his lab in 2013 cost about $330,000.
It currently costs around $50,000 to produce one pound of meat in vitro, and that’s mostly because of the culture media. Fetal Bovine Serum (FBS), which is probably the most important ingredient, can cost up to $1000 per litre!
Additionally, FBS does, as it sounds, come from cow fetuses. Due to the (very painful) way it is sourced, it does not align with the ethical intent of cellular agriculture — to be unreliant on animals. People for the Ethical Treatment of Animals (PETA) has devised a comprehensive list of plant-based substitutes for FBS, but none of them were considered to be quite as effective as FBS.
Why?
The blood of fetal calves is often called a cocktail “because there’s something for everybody”. Besides the essential nutrients, most mammalian cells require things called “growth factors” to grow. In an animal, these growth factors are supplied by the animal’s blood. So, using FBS is a pretty intuitive way to conveniently source them all.
Researchers at the University of Taiwan are looking into alternatives to FBS. Thus far, their comparison has included things like newborn calf serum, cosmic calf serum and iron supplemented calf serum (which, yes, are just other types of cow blood). Many of them achieved similar effectiveness as FBS. And while they are not ideal, they differ from FBS in that they are continuous sources, they can be obtained at a reduced price, and do not necessarily require painful treatment to the animal — which were some of the biggest challenges with FBS.
And, if we want to eliminate the role of the animal entirely (which we do), our current alternative is recombinant protein production which involves synthesizing each growth factor individually. This is usually very expensive.
But luckily, as researchers are starting to demonstrate the effectiveness of these “serum free culture media”, they’re also considering how to produce them cheaply. A popular analysis by the Good Food Institute has put forth a series of realistic modifications that could be made to the Essential 8 Culture Medium that would allow it to be produced for as little as $1.37 per litre.
Companies like Future Fields, Biftek and Multus Media are also working on coming up with other serum free culture media that are as effective and can be produced at lower costs.
Continuing in this vein, as much as cellular agriculture aims to be unreliant on animals, since it by definition entails culturing a set of animal cells, we can not be completely animal independent. We can, however, limit the amount of cells that we do directly take from the animal.
Ideally, we could get it to the point where one group of cells produces all the meat we ever need! This requires sustaining one cell line indefinitely. Naturally, this is impossible because of the Hayflick limit, which implies that cells can not replicate forever. Satellite stem cells, which are just a specific variation of stem cells, can duplicate at most 40 times.
One way we can get around this is by creating stem cells called Induced Pluripotent Stem Cells (iPSCs). These cells are created by taking a normal specialized cell and editing its DNA so that it returns to being a stem cell — kind of like reverse engineering.
On the end of a DNA strand, there is a protective telomere cap. When our cells divide these telomere caps get shorter and shorter until they are nonexistent and the cell becomes senescent cells — which for our purposes, basically renders them useless. When we reverse engineer our cells, we can make the telomere long enough so that it exceeds the Hayflick Limit and our cells are effectively immortal!
Is this actually viable?
The short answer to that is not yet, but almost. Over the last century, a lot of progress has been made in this field in taking it from an idea to science to a commercial product. As of the end of 2019, there were 55 companies in 19 countries around the world who are working on bringing cellular agricultural products to consumers.
Just to highlight a couple…
Memphis Meats is a startup founded by Uma Valeti and Nicholas Genovese. In 2016, they created the first cultured meatball, and a year later, the first cultured poultry. The company is thinking about producing gourmet foods because the cost to produce them in vitro is the same as producing more accessible products, but they can demand a higher price for them. They hope to bring their products to market by 2021.
Another notable company is Perfect Day started by Ryan Pandya and Perumal Gandhi. These entrepreneurs were unsatisfied with the personal sacrifices they had to make in order to eat more sustainably and sought after a way to resolve this. They work with acellular agriculture, and engineered a yeast which converts sugar into raw milk protein. They are selling this to other companies in a business to business model.
At the end of 2019, there were 55 companies working in cell based products around the world. Some of them include Aleph Farms, JUST, Modern Meadow and Finless Foods. A number of these companies have received Series A funding from successful figures and companies such as Bill Gates, Richard Branson, Temasek and Tyson & Cargill.
The majority of these companies are still in their developmental stages, with some of them already building pilot plans. Commercialization will introduce a whole other set of hurdles.
Firstly, few countries actually have any set guidelines and regulations which govern the production and selling of cultured meat. Although, recently, the USDA and FDA announced a joint responsibility for cellular agriculture products with each organization overseeing part of the process. The Good Food Institute is assisting various governments in coming up with their own policies that can support the industry. Additionally, Cellular Agriculture Canada recently released a white paper covering suggestions for the existing regulatory space in Canada. For starters, many existing laws are somewhat problematic. For instance when used in marketing, terms such as “meat” and “meat products” specifically refer to animal slaughter.
Then there’s public acceptance. As the technology is quite new and unfamiliar to people, it will take some getting used to in order for consumers to feel comfortable enough to want to buy it. Like with anything, this can be done through education and awareness. Organizations like CellAgri and Cellular Agriculture Canada aim to do this by keeping people up to date with what’s going on in the industry.
Key Takeaways
- Cellular agriculture is all about producing animal products WITHOUT raising the animals. In the case of cellular agriculture, this is done by extracting stem cells from a living animal, immersing them in a culture medium so that they proliferate, seeding them onto a scaffold for structure and placing it in a bioreactor so that they differentiate.
- It is much better for our environment than traditional agriculture because it uses fewer natural resources, less energy and produces fewer greenhouse gas emissions. It also has huge positive implications for animal welfare.
- A big challenge to cellular agriculture is cost. Currently, producing animal products in vitro is ridiculously expensive, and this is mainly due to the cost of the culture medium. Scientists are currently working on developing animal-free culture media that are effective and can be produced cheaply.
- There are several new companies working on bringing cellular agriculture products to market. The main challenges they’ll probably have to overcome are the lack of existing regulations within the industry as well as public acceptance.
Our food production system has been around for thousands of years, and it’s only gotten more wasteful. Cellular agriculture is a technology that has the potential to change this, ultimately allowing you to eat everything you’ve always eaten, only produced in a much more responsible way.
