Could Genetically Engineered Fungus Help Replace Animal Protein?

Scientists grew a microscopic fungus into a more efficient — and meat-like — edible protein by tweaking just two genes with CRISPR gene editing.

A team led by researchers at Jiangnan University removed two genes from the genome of Fusarium venenatum, the fungus used in the meat substitute Quorn. The newly modified fungus is more nutritious and less resource-intensive than the original strain — and much more so than meat. The authors reported that the modified strain, which they call FCPD, produced 88% more protein while consuming 44% fewer nutrients than the original fungus. The paper was published in Trends in Biotechnology on November 19.

“We successfully made a fungus not only more nutritious but also more environmentally friendly by tweaking its genes,” corresponding author Xiao Liu says in a press release. André Damasio, a microbiologist at the State University of Campinas in Brazil who was not involved in the research, tells Sentient that the researchers were “very successful” at increasing the fungus’s growing efficiency.

This efficiency could help popularize mycoprotein with consumers by bringing down costs, says Damasio, who is also the scientific adviser for the mycoprotein startup UpDairy. “If you reduce the sugar amount, you directly can reduce the price of the final product,” he says.

Packed With Protein

As climate experts call on wealthy countries to reduce meat consumption, alternative proteins are needed to help curb meat’s planet-warming emissions. High-protein plants like legumes are the most efficient way to provide protein, but fungal protein — also called mycoprotein — could help consumers shift away from meat by offering a nutritious alternative to animal protein. Mycoprotein has a high protein content while also providing more fiber than meat.

The microscopic fungus Fusarium venenatum has been cultivated for edible fungal protein for decades. The species was first developed as an edible protein in the late 1960s by a British company seeking new protein sources for a growing global population.

In commercial production, the fungus cells are fed with sugar and nitrogen to grow into a soup-like paste. This soup is then heat-treated and mixed with a binding agent, typically either egg white or potato protein, for a palatable meaty texture. Mycoprotein from F. venenatum was approved for sale in the United Kingdom in the 1980s and has been sold as the Quorn brand of meat alternatives ever since.

Quorn has shown that mycoprotein can be commercially viable on a moderate scale. Quorn’s U.K.-based parent company Marlow Foods reported the equivalent of almost US$250 million in sales in 2024, despite a 9% year-on-year drop amid diminishing consumer interest in alternative proteins.

Questions of flavor and texture remain before mycoprotein can find stable widespread popularity, but CRISPR gene-editing techniques could change that, Ramona Cheriaparambil, a food scientist and Ph.D. student at the University of Massachusetts, tells Sentient in an email.

That’s also the hope of the Jiangnan University researchers. In the new study, they used CRISPR to remove two genes. Knocking out the first of these genes made the fungus grow more efficiently, requiring less sugar input to produce the same amount of protein. Taking out the second of these genes reduced the amount of tough chitin in the cell walls. Chitin is a molecule found in the cell walls of fungi and the exoskeletons of insects and crustaceans. Less chitin made the fungal cell walls thinner, enabling humans to more easily digest the fungus and get the protein inside it.

The researchers also tested the texture and digestibility of two modified F. venenatum strains, including the FCPD strain, in another recent paper published in Food Research International on September 15.

The FCPD strain had better taste and texture than the other modified strain thanks to its higher fat content. In addition, they both showed clear improvements in palatability over unmodified fungus. A very game 27-year-old volunteer chewed and spat out pan-fried samples. The researchers fed the chewed-up wads into a texture analysis machine that squashed and prodded the samples to measure their hardness, adhesiveness, resilience, cohesion, springiness, gumminess and chewiness. They found that the texture of both of the engineered strains closely resembled chicken breast.

In the first paper, the authors performed a detailed analysis of the environmental impacts of different protein production methods. The new fungus strain had a larger footprint than plant protein, but compared favorably to the unmodified fungus, cell-cultured meat and chicken meat.

Compared to chicken production in China, protein from FCPD would need 70% less land and would reduce the risk of freshwater pollution by 78%, the researchers found. (And chicken generates relatively low emissions compared to other meats such as beef and lamb, which the researchers did not include in their analysis.) Sausage made from pea protein had the lowest environmental impact of the proteins analyzed.

CRISPR Promise

Damasio says that the efficiency improvements demonstrate CRISPR’s effectiveness with fungi. “They did only two deletions, only two mutations, and increased the process efficiency” by about 40%, Damasio says. “That’s amazing — it’s very difficult to do it using classical genetics or other strategies.”

Cheriaparambil notes that skepticism around genetically modified foods remains a major obstacle to mainstream consumer appeal — but regulators, at least, have previously allowed CRISPR techniques because they merely deactivate genes without using foreign DNA. That’s why the U.S. Department of Agriculture ruled in 2016 that a CRISPR-modified strain of a common mushroom could become the first such organism to enter the market without undergoing a review.

“Since it’s more sustainable compared to cell-cultured meat and animal proteins, it definitely has great potential,” Cheriaparambil writes by email. “But there’s always scope for improving its sustainability index in comparison to ingredients that have a lower footprint, like pea proteins.”

New ways of producing non-animal protein may have a role in shifting wealthy nations’ protein consumption away from meat. Fungi optimized with powerful, efficient gene editing could be one more way to meet the world’s protein needs.