The "Cow of the Sky" project - producing milk from the air

The Cow of Heaven project aims to find a way to produce milk protein from bacteria that feed on carbon dioxide and hydrogen

The milk from the air in the center of the image will replace that of the cows grazing outside. Credit to the science site, via DALEE
The milk from the air in the center of the image will replace that of the cows grazing outside. Credit to the science site, via DALEE

You can find videos in this style all over the web: a woman (or man) enjoying the taste of a whitish liquid on her lips. Sometimes in such large quantities that it dribbles from the mouth and drips down the chin. The viewers are captivated and the reviews praise. Entire websites have been set up to host and distribute these videos.

Yes, there is no doubt that milk is one of mankind's favorite foods.

Unfortunately, it is also very polluting. 

It's easy to forget the origin of milk when we buy it in the supermarket, but the nutritious liquid comes from cows. A typical cow weighs about 700 kilograms, which is made up of muscles, bones, fat, nerves and other tissues. The cow consumes large amounts of food and water - which are costly to the environment - to support all this biological mass. And if that's not bad enough, it releases byproducts like methane: a greenhouse gas that accelerates global warming.

The solution? A new European project called Hydrocow, or in my (very) free translation, "Cow of Heaven". 

The project was launched at the end of 2023, with a grant of six million dollars from the European Innovation Council. It was designed to find a way to produce milk protein from bacteria that feed on carbon dioxide and hydrogen. During the four years of the project, the researchers will try to genetically engineer bacteria that will produce the beta-lactoglobulin protein, which is one of the main proteins in milk and gives it its unique taste and texture. The engineered bacteria will be tested by the Solar Foods company. And if they succeed, well, then by 2030 we may all be enjoying milk that has never seen a cow's udder. And accordingly, it will also be cheaper, and will certainly harm the environment less.

And when it happens, it won't be a big surprise - since it's a bigger trend than the last century, which has already earned its own name: the second fermentation revolution.


The fermentation revolutions

Fermentation is the process in which bacteria - or other microscopic creatures - break down raw materials and produce by-products that serve humans. The human race has been making such use of microorganisms for tens of thousands of years, even if we didn't realize it until recently. The alcohol in wine and beer, for example, is the product of the fermentation activity of bacteria or yeast, which receive plant material as food and produce ethanol in return. 

In the first fermentation revolution, we discovered processes that allow microorganisms to work optimally - for example, picking grapes, crushing them and keeping them in barrels at the right temperatures to turn them into wine - without understanding why these processes work so well. Most of the time we were not even aware of the existence of the microorganisms. Only in the last two hundred years have we become aware of the beneficial action of the bacteria, yeast, algae and other tiny creatures that surround us. And only in the last fifty years have we begun to try to engineer them on purpose, so that they do their job better, for man. This is the "second fermentation revolution".

The second fermentation revolution has already had very impressive successes. Most of the cheese in the United States, for example, is currently produced with the help of an enzyme called chymosin - which is produced from a bacterium that has been genetically modified for this very purpose. The bacteria thereby replaces the calves, because in the past it was customary to extract a similar enzyme from the stomachs of calves. Even insulin, which is used to treat diabetes, human growth hormones and even some vaccines are now produced by bacteria in laboratories and factories.

No wonder, therefore, that there is a strong desire in the food industry to develop bacteria that will produce milk proteins. In fact, there are already companies today that are trying to reach similar achievements. One of them is the Israeli company Remilk, which has engineered yeast for the production of milk proteins. The problem is that those tiny creatures need food rich in sugars, which usually comes itself from plants grown in agricultural areas.

In the "Cow of the Sky" project, the bacteria are supposed to get most of their nutrition from the air. More precisely, they will be able to break down the carbon dioxide in the air. This particular gas is abundant in the Earth's atmosphere and contributes to the greenhouse effect that accelerates global warming. In other words, the bacteria that will be developed in the project will be able to break down one of the harmful substances in the atmosphere today - and turn it, plus some hydrogen that will come from water, into one of the most popular foods in the world. for milk, and it is to be assumed that later also for cheeses of all kinds.

"If the Hydrocow project is successful, it will enable new biological production methods that focus on nutrition and do not rely on photosynthesis and traditional agriculture." was explained in a press release which was released by Ginkgo BioWorksf, one of the companies involved in the project. "These methods will be replaced by the conversion of atmospheric carbon directly into milk proteins, in a process that saves time, energy and land."

A representative of the Solar Foods company was More direct in his words

"[The technology] will be orders of magnitude more efficient and environmentally friendly than traditional dairy farming." A message to the media, and a message to the entire industry. "It takes agriculture out of the equation."

on the project website It is estimated that the reduction in the cultivation areas and the amount of water required to produce milk will be reduced by 99 percent compared to the traditional method of milk production. 

But of course, promises come easily. What about the implementation?


Big promises - and big risk

Big promises are often also accompanied by big risk, and this is also the case in the "Heaven of the Sky" project. In fact, the project itself is defined as "big risk, big return". Perhaps, among other things, because the scientists involved aren't even sure exactly how to get the bacteria to do as they please and convert carbon dioxide and hydrogen into the desired proteins at a high rate.

This is why, in the first part of the project, the researchers are going to collect all the information - past experiments, literature, personal experience - about the 'technologies' that turn excellent microorganisms into excellent protein producers. The word 'technologies' refers to the genes that control the way these microorganisms work. These are, in the end, technologies because they are pieces of code that control the actions of the cells, and they can be duplicated and adapted to improve the ability to create milk proteins in bacteria.

In the second phase of the project, the researchers intend to set up a circle of "Planning - construction - examination - learning". They will design the bacteria so that they include the most suitable pieces of code for the production of milk proteins, build them using genetic engineering tools, test them under laboratory conditions - and draw conclusions on how they can be improved even more. This cycle of constant improvement will repeat itself as necessary and as much as possible The duration of the project, until the desired results are obtained - then the bacteria will be transferred to the Solar Foods company, which will check whether it can really use them to produce milk from air.

As a biologist in the past, I am particularly enthusiastic about the cycle of continuous development and improvement offered by researchers. In the past, it took months of research to make even a small genetic change in bacteria. Today, thanks to modern genetic engineering tools, it is possible to create significant changes in bacteria within weeks, or even a few days. This efficiency, along with the ability - which will surely be assisted by artificial intelligence - to collect a lot of information from the literature and derive insights from it regarding the best way to engineer the bacteria, makes me believe that the project has a better chance of success than expected.

With all the optimism, it is still a gamble. Every project in the field of biology and genetic engineering is always more complex than it seems at first, and many are the researchers who went bald during the PhD after tearing out all the hair on their heads in frustration, experiment after experiment. 

But what if the project succeeds?

Imagine a world where milk flows like water, and is almost as cheap as them. A world where every child in a third world country can enjoy the nutritious drink high in proteins and fats. A world where cheese prices - which are ultimately a product of processing the milk - drop to zero. Mozzarella, parmesan and all the rest. A world of cheap pizzas.

I repeat again: a world of cheap pizzas.

For that alone, it's worth waiting for the future.

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