Humans have been using bacteria and fungi, including yeast, for millennia to make foods both tastier and extend their ‘shelf life’. Thus, even in ancient times, bread, beer and wine, soy sauce, fermented dairy products and vinegar could only be made with the help of microorganisms. Thanks to naturally present yeasts and bacteria, sugar was converted into acid or alcohol and CO2. The microorganisms that cause spoilage or disease do not like acid, nor do they like a drink. Subsequently, they had no chance once food was fermented.

Of course, humans didn't understand the underlying processes until the modern era arrived and Louis Pasteur’s theories on fermentation were published in 1858. Thanks to his work combined with the industrial revolution, the budding food industry started to ferment more and more over the decades. Breakthroughs in genetic modification in the 1970s and 1980s opened doors to all sorts of new applications. In addition to certain foods, we owe other materials, chemicals and medicines such as rubber, acetone and insulin to the fermentation process.

Umami Candida
Specifically in the food industry, fermentation technology began to scale up around 1880, when the production of baker's yeast took off in the United Kingdom. During World War I, baker's yeast was widely cultivated in Germany to serve as a protein source. In World War II, the Germans repeated this trick, but with Candida utilis (Torula yeast), grown on the waste streams from the wood and paper industries. Torula is still used, but mainly as a flavouring agent as it naturally has a smoky umami flavour.

Meanwhile, Westerners still rarely eat yeast as a protein source. A shame, because many yeasts are complete proteins: the amino acid profile is almost perfect for us
Nowadays, Westerners eat but rarely yeast as a protein source. A shame, because many yeasts are complete proteins, the amino acid profile is almost perfect for us. But this sorry state of affairs now seems to be changing; many investors discover fermentation as the technology of the future when it comes to alternative proteins. According to a report by Good Food Institute (GFI), of the $1.5 billion pumped into meat substitutes in the first half of 2020, a third went specifically to fermentation techniques.

Tasty fungi
The first food manufacturer who used fermentation on a large scale to make protein for human consumption, was Marlow Foods, the original producer of Quorn. This involved mycoprotein: protein based on mold. The company produced Quorn by growing the single-celled fungus Fusarium venenatum and then processing it into something tasty. Quorn is an example of biomass fermentation; the company uses the entire mass of microorganisms to produce their fake chicken. In addition, it is a form of single cell protein, an umbrella group that also includes microalgae, such as spirulina and Chlorella. Unlike fungi and most bacteria, however, microalgae grow not by fermentation but by photosynthesis.

Efficient waste eaters
In the most common method of biomass fermentation, the food for the microorganisms consists of organic materials, particularly sugars. In the case of Quorn, it started with a starchy residue from the processing of grains. This is one of the main advantages of the technology: residual streams from other processes can be used as food.

The yeast Saccharomyces cerevisiae also grows on organic material, usually on glucose syrup. It is one of the most widely used microorganisms, both in research and in industry. The different strains of Saccharomyces cerevisiae are used to brew beer and bake bread, or used in their deactivated form as nutritional yeast, among other things. In addition, the biomass of yeast used in brewing is reused to make yeast extracts such as Marmite and Vegemite. This can be seen in the nutritional value of these spreads; Marmite consists of 39% protein. Eating an entire jar is not recommended, by the way, not only for the taste, but also because it contains 6% salt.

Kefir is also an example of biomass fermentation of fungi, but in this case, it is a symbiotic mixture of yeast and bacteria. Although the kefir grains are usually separated from the fermented milk for consumption, they can also basically be eaten simply as a protein-rich food.

The nutritional value of fungi
According to a review into the state of single cell protein, fungi contain about 30-50% protein on average. This protein is also complete according to the United States Food and Agriculture Organization (FAO) guidelines. Although fungi do not naturally produce vitamin B12, they are a rich source of other B vitamins. In addition, they provide fiber.

[n]Fungal Swedish Balls
Although Quorn's mycoprotein patent expired back in 2010, it is still the only mycoprotein sold in Europe. “This is presumably due to high start-up costs,” former CEO Kevin Brennan said in a 2011 interview. Huge fermentation tanks are apparently pricey. U.S. based companies Meati Foods and Nature's Fynd have both since then brought myoprotein products to the U.S. market anyway. In addition, Swedish start-up Mycorena began producing mycoprotein in 2018 with the motive of making meat substitutes that require less land and water use than real meat production, as well as meat substitutes from plants. Mycorena's goal was originally B2B (Business to Business), to have their fungal protein incorporated into products by other parties. In June 2020, they launched a trial with vegan Swedish meatballs. This was successful, as the meatballs are completely sold out according to the website.

Depending on the type of bacteria, bacterial biomass can also use sugar-rich residual streams from other industries as food, similar to yeast
Methane eaters
In addition to fungi, there are also bacteria that are used in this way. Currently, this is done mainly for animal feed, among others, by Calysta Inc., Imperial Chemical Industries, and UniBio A/S. Depending on the type of bacteria, bacterial biomass can feed on sugar-rich residual streams from other food industries, just like yeast. The beauty of the newer processes from Calysta and UniBio, however, is that they use methane as a nutrient. A technical research center in Finland has already found a way to combine production with methane capture in livestock farming. Now that's a circular process.

The protein content of bacterial biomass is somewhat higher than that of yeast; about 50 to 80% on average. The amino acid profile is equal to, and in some cases even better than, the FAO guidelines. Unlike algae and fungi, certain strains can even make vitamin B12.

Dairy thanks to bacteria from gorillas
One company that is already successful with bacterial biomass for human consumption is Superbrewed Food. This company cultivates bacteria to make a product with 85% protein. The company uses the whole bacteria instead of isolating the protein. According to an article by FoodNavigator, the product is very similar to milk, so Superbrewed Food sees opportunities for dairy alternatives, including cheese. In addition to protein, the bacterial mass contains small amounts of fiber and other carbohydrates. The microorganisms also produce vitamins and minerals, including a nice amount of vitamin B12.

Fun Fact: Superbrewed Food looked to gorillas to develop the technology.
Gorillas eat entirely plant-based foods but are still able to develop gigantic muscles. The bacteria in their gastrointestinal tract are apparently very good at converting plant matter into protein. By using bacteria similar to those found in gorillas, the company can make proteins from plant material very efficiently.

Protein from the air
Next to bacteria that need organic matter to grow, there is also a group that can grow from a mixture of CO2 and hydrogen. These hydrogenotrophic bacteria (nice word for Scrabble) were already being investigated by NASA in the 1960s in order to make food in space. It may sound like the photosynthesis that plants use to grow, but this process is a lot more efficient. The biomass grows about 20 times faster than plants and it hardly requires any land.

Superbrewed Food looked to gorillas to develop the technology. Gorillas eat entirely plant-based yet are able to develop gigantic muscles
Several companies are already using this technology. Finland's Solar Foods makes Solein, a neutral-tasting powder. Splitting hydrogen from water requires electricity, for which process the company uses solar energy. The powder consists of about 65% protein, 20-25% carbohydrates, and 5-10% fat. The company did apply for approval by the European Food Safety Authority (EFSA), which is expected to take more than a year. Obviously, it will take some time to build large-scale production facilities. With a nutritional value similar to soy and algae and with a mild taste, Solein can be very widely used/applied in products. The company expects to market about 20 different products with Solein by the end of 2022.

Deep Branch is a company working on this technology in the UK and the Netherlands. Currently, the company produces a powder called Proton™, which is already used in animal feed. Whereas Solar Foods produces its own hydrogen and captures CO2 for production, Deep Branch uses hydrogen and CO2 generated in industrial processes. By connecting a ‘mini factory’ the size of a shipping container to an industrial plant, the gas can be directly reused. Although Deep Branch doesn't seem to have any plans to use Proton™ as human feed, the land gain compared to regular livestock feed is a big win.

The American company Air Protein also uses hydrogenotrophic bacteria and renewable energy for its production. Inspired by NASA's research, this company is currently making a powder, but the ultimate goal is to produce a true meat analogue. The company goes a step further than Solar Foods and Deep Branch. In addition to protein-rich products, they also found ways to make different types of oil with specific compositions, including a palm oil analogue. Founder Dr. Lisa Dyson gave an inspiring TED Talk about the process already in 2016.

Precision fermentation
In addition to producing microorganisms that humans can eat whole, fermentation can be used to make very specific substances. The precision with which protein functionality can be targeted, is a major advantage, even though some suger is required as nutrient for the fermenting organisms. With a few exceptions, the development of real products is now at a stage somewhere between science fiction and the store aisles.

Six years ago, Foodlog wrote about Muufri, a Silicon Valley company that wanted to recreate real milk without cows. By inserting cow DNA into yeast cells using genetic modification, these cells produce the same proteins and fatty acids that normally are produced in milk by a cow. The company has been renamed Perfect Day Foods. The whey proteins the company produces are already used commercially. Under the name Brave Robot, US consumers can buy ice cream made with Perfect Day's synthetic milk proteins. The ice cream apparently is allowed as GMO-free by the U.S. Food and Drug Administration (FDA), since the organisms themselves are not in it.

Legendairy Foods was the first European company to engage in dairy from yeast
Impossible Foods does something similar to produce leghaemoglobin, the ingredient that makes their fake burgers so ‘meaty’. Instead of using the heme from animal blood, the company produces plant heme that is also found in the roots of legume plants. However, thanks to genetically modified yeast, the company does this much faster than plants can. Although heme does not serve as the primary protein source in the Impossible burgers, this is a great example of the possibilities of precision fermentation.

Silicon Valley is home to many start-ups that use precision fermentation in their quest to create animal-free animal proteins (and sometimes other products). For example, Clara Foods is engaged in the production of animal-free eggs, baking products, and ingredients for the food and beverage industry, among other things. Motif FoodWorks works on meat and dairy alternatives, while Change Foods is specifically focused on dairy suitable for cheese making. New Culture does things a little more specifically and makes mostly casein, the main protein in cheese making. As these are all American companies and the difference in regulations between the U.S. and European markets is substantial, we're probably not going to see these companies' products here anytime soon.

Legendary real fake milk
A little closer to home operates the British company Better Dairy. However, this start-up is still so young that its website is virtually empty. I suspect that Better Dairy will do something with dairy. My nomination for the most original name goes to Germany's Legendairy Foods. This was the first European company to deal with dairy from yeast. Since its founding in 2018, the company has been perfecting their technique. Fat chance that products from Legendairy Foods will be the first we will find on shelves in Europe.

According to trade magazine Food Ingredients First, Those Vegan Cowboys have also taken their first steps in precision fermentation. Foodlog previously wrote about the former Vegetarian Butchers and their ambition to make tasty cow-free cheese. The company is actively developing their own technology for real fake cheese. Perfecting and scaling up the technology and then getting approval from the European Food Safety Authority (EFSA) is still going to take a few years, but this step is promising.

In Europe, the use of genetic modification in food is subject to rather strict rules
Thanks to the efforts of researchers at the American J. Craig Venter Institute, it has been possible to make synthetic genes since 2010. In 2012, a team led by Jennifer Doudna and Emmanuelle Chapentier developed the CRISPR/Cas9 technique, which made cutting and pasting pieces of genes a breeze. Thanks in part to developments like these, we can now get bacteria and yeast cells to do even more slick tricks. For instance, they could clean up oil spills, or make certain substances in a very targeted way, as is already done in precision fermentation. Apart from fermentation, companies such as Moolec Science can also use genetic modification for molecular farming, allowing plants to produce animal proteins.

In Europe, the use of genetic modification in food is subject to rather strict rules. A new product must meet a long list of conditions and undergo extensive testing before it is approved. However, a number of types of biomasses made by fermentation with modified yeast and/or bacteria have already been approved.

As with cultured meat, consumer acceptance will be a major obstacle before these types of products catch on. After all, GMO also feels "unnatural" to many people, and bacteria additionally 'dirty'. Personally, however, I am very curious about what the future will bring and I will probably be at the front of the queue when the real fake cheese hits the shelves. It's going to be legendary.