DEEP in the , far from any cows, the future of meat is taking shape. This time next year, a 5000-litre bioreactor could be up and running with the goal of eventually growing enough synthetic flesh to provide 2000 people with their annual meat ration.
This is the vision of Mosa Meat, launched last week by , whose lab-grown beefburger was cooked and eaten on live television in 2013.
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The launch coincided with the first-ever , held in Maastricht. Around 100 scientists met to discuss the promise and pitfalls of meat made without animals. Tissue engineers presented new ways to grow flesh, social scientists discussed its public acceptance, and biological engineers highlighted the vast scale needed to produce the stuff in useful amounts.
Trying to grow meat in a vat, rather than raising and killing animals, makes sense if we want to continue eating it in large quantities while preventing further damage to the environment – and maximising animal welfare. A 2006 report from the UN Food and Agriculture Organization paints a clear picture: livestock farming is one of the “most serious environmental problems, at every scale from local to global”. Beef is the : producing 1 kilogram uses 15,000 litres of water and into the atmosphere.
According to a 2011 analysis by Hanna Tuomisto at the University of Oxford, far fewer greenhouse gas emissions, and use much less water and land (see chart).
So could we get to a point where synthetic meat replaces farm animals? In essence, the process is simple. Take stem cells from animals (see “Will vat meat ever replace animals?“), feed them and allow them to divide and grow into a big chunk of muscle cells. There are several key challenges in this, however, one of which was spelled out by meeting attendee Chris Hewitt, a biological engineer at Aston University in Birmingham, UK. Unlike most bioengineering on the planet today, he points out, culturing meat means growing cells as a product, not using them to make something else.
Bioreactors typically use cells to produce useful proteins, then discard the cells. For example, the breast cancer treatment herceptin is made using genetically modified hamster ovary cells in gigantic 25,000-litre vats. Human insulin comes from modified E. coli bacteria and the statins used to treat heart disease, are made in yeast cells. “I’ve spent my career growing cells in tanks,” Hewitt says. “It’s very rare that the cell is the basis of the product.”
The difficulty is keeping them alive – making sure they have a constant supply of oxygen and food. Growing a giant blob of cells doesn’t work, as the cells in the centre die for lack of oxygen.
One way to get around this is to grow the cells on a surface of tiny plastic beads that facilitates the flow of oxygen and nutrients. Companies like Janssen in the US do this in vats with a capacity of up to 1000 litres, but it is a relatively expensive and complicated process.
Blood and fat
Because of this, producers have now figured out ways to adapt the cells to operate in a suspension. Floating free in a vat allows cells to be grown at much higher densities and in greater quantity.
But Post’s business partner points out that getting a 5000-litre bioreactor up and running does not mean Mosa will be producing edible artificial meat right away.
Like all cell cultures, the meat cells rely on a feedstock containing nutrients and growth hormones. For cultured beef, this means including 5 per cent bovine fetal serum. This is a substance derived from blood collected from the heart of an unborn calf after its mother is slaughtered. It is a “by-product” of the dairy industry, in the sense that dairy cows are routinely disposed of after a certain number of years, but it negates for the time being any potential environmental or ethical advantages to be gained from cultured meat. Post hopes to eliminate the need for this in the long run.
“The meat cells rely on a feedstock containing bovine fetal serum, derived from slaughtered cattle”
The rest of the nutritious goop fed to the cell culture is ethically unobjectionable, but is nevertheless expensive, appropriate for the relatively small scale needed for medical cultures but not for food production on an industrial scale.
Nor will Mosa’s final product bear much resemblance to actual meat. What comes out of the vat is a collection of muscle cells, white until coloured by beetroot and lacking in the real-meat flavours provided by blood and fat.
Post hopes to find solutions to these problems as they go along. “We want to end up with a 25,000 litre bioreactor – enough to provide meat for 10,000 people a year, at European consumption levels,” he says.
“We want to end up with a 25,000-litre bioreactor, enough to feed vat meat to 10,000 people a year”
Still, even this ambitious target is nothing compared with the scale required to make any kind of dent in global meat consumption. Hewitt and his colleague Qasim Rafiq estimate that total bioreactor space available on the planet at the moment amounts to, at most, 1 million litres. If all this space was turned over to cultured meat production, it would provide meat for just 400,000 people.
So we will need to dramatically improve the efficiency of the cultured-meat producing process, not to mention building a lot more steel vats.
This scale means alternative solutions are likely to win in the short run. For example, rather than muscle cells, it may make more sense to focus on producing synthetic versions of the things that make meat delicious – blood and fat – to flavour non-animal-derived protein.
David Zilber, a chef at Michelin-starred Norwegian restaurant Noma who attended the meeting, says that meat is more of a concept than a specific substance, defined by taste, smell and texture rather than any one source. After two days listening to tissue engineers and food scientists detail their struggle to produce anything that resembles real meat, Zilber concludes that a bioengineered meat broth might be a more useful first product to aim for, perhaps to accompany ramen noodles. And other vat-derived components could help push non-animal protein sources such as soya over the edge into meatiness.
Verstrate agrees that focusing on particular characteristics, and bioengineering for flavour, rather than structure and calories, may have merit. “I do see this Lego approach emerging in the future,” he says.
Meanwhile, the market for meat substitutes is taking shape, with multiple start-ups, mostly in the US, coming onto the scene. Los Angeles-based Beyond Meat uses pea protein to mimic meat structure, for example, and Impossible Foods in Redwood City in California, is developing a mixture of plant-derived proteins to make meat-like patties. Dutch company Beeter and British firm Quorn both have sizeable market shares in imitation meat.
“There’s an ecosystem building to make animal products without animals,” says Isha Datar, CEO of New Harvest, a non-profit which advocates and raises funds for animal alternatives.
Along with growing muscle, Post’s lab at Maastricht University has now started work on synthesising fat from stem cells. And if the chef’s word is anything to go by, that could be where the big advances are made. “Blood and fat is what makes meat,” says Zilber. “Muscle is just the vehicle.”
Read more: “Struggling to find an appetite for cloned meat”
(Image: Reuters/David Parry)
Will vat meat ever replace animals?
If we work out how to make artificial meat on a global scale, what would the world look like? Will farm animals simply disappear?
The transition will not be a sudden one, but even then domesticated livestock will be needed. They will be valued for the stem cells that are the foundation of meat cultures. “Adult stem cells have a limited lifetime,” says Post. “You need to keep a donor herd.”
This means that producers will need to keep returning to live herds for stem cells, which can be taken without harming the animal. Future herds might become semi-wild, only tracked down when it’s time for a new batch of cells.
Cell cultures currently rely on fetal serum taken from the appropriate species. But even if no alternative is found, livestock would be far fewer in number, and with no need for intensive farming there would be an end to the most environmentally destructive, high-density feedlots.
David Zilber, a chef at Danish restaurant Noma, says that in a world where artificial meat is mainstream, there would be a market for high-quality real meat, produced in a way that is as ethically and environmentally friendly as possible.
This article appeared in print under the headline “Meat without murder?”
