The convergence of biotechnology and culinary innovation is reshaping the landscape of what we eat. With animal-free dairy alternatives and convincing vegetarian meat substitutes already disrupting the market, these changes are increasingly evident, and the trend is not slowing down. Advancements in genetic engineering are unlocking new pathways to produce cruelty-free products that cater to both consumer health and environmental sustainability.

At the forefront of this culinary revolution is the exploration of fungi, a diverse kingdom of organisms that naturally yield a vast array of proteins, fats, antioxidants, and flavor compounds. By modifying fungal genes, Chef-turned-bioengineer Vayu Hill-Maini is working to expand the already vast range of flavors and textures offered by these organisms.

“I think it's a fundamental aspect of synthetic biology that we’re benefiting from organisms that have evolved to be really good at certain things,” Hill-Maini, an affiliate with the Biosciences Area at Lawrence Berkeley National Laboratory, explains. “What we're trying to do is to look at what is the fungus making and try to kind of unlock and enhance it. And I think that's an important angle that we don’t need to introduce genes from wildly different species. We’re investigating how we can stitch things together and unlock what's already there.”

In a study published in Nature Communications, Hill-Maini and collaborators from UC Berkeley, the Joint BioEnergy Institute, and the Novo Nordisk Foundation Center for Biosustainability delved into the genetic manipulation of Aspergillus oryzae, commonly known as koji mold. This multicellular fungus, traditionally utilized in East Asian cuisine for fermenting starches into sake, soy sauce, and miso, served as the foundation for their experiments.

Employing CRISPR-Cas9 technology, the team developed a precise gene editing system capable of systematically modifying the koji mold genome. By fine-tuning specific genetic pathways, they enhanced the fungus's ability to produce key compounds essential for food applications. Notably, efforts were directed towards augmenting the production of heme, an iron-based molecule responsible for the color and flavor of meat, and ergothioneine, an antioxidant associated with cardiovascular health benefits.

The outcome was striking: the once-pale fungi transformed into a vibrant red hue, offering the potential to be fashioned into appetizing burger patties with minimal processing.

Looking ahead, Hill-Maini aims to further enhance the appeal of fungal-based foods by manipulating genes governing texture and lipid composition. “We think that there's a lot of room to explore texture by varying the fiber-like morphology of the cells. So, we might be able to program the structure of the lot fibers to be longer which would give a more meat-like experience. And then we can think about boosting lipid composition for mouth feel and further nutrition,” said Hill-Maini. “I'm really excited about how can we further look at the fungus and, you know, tinker with its structure and metabolism for food.”

While these developments represent just the tip of the iceberg in harnessing fungal genomes for food innovation, they underscore the immense potential of these organisms as sustainable protein sources. While cultured meat has received major attention in the realm of sustainable protein alternatives in recent years, its pathway to consumers has been plagued by cost barriers and technical difficulties. Multicellular fungi, on the other hand, are cheap and easy to grow in large quantities and avoid the long and complex ingredients list of cultured meat. 

Additionally, the editing toolkit developed by the team represents a major breakthrough in allowing the manipulation of the complex genomes of multicellular fungi. Their long history in food production is a testament to the culinary capacity of these organisms, and introducing the ability to manipulate these organisms promises a myriad of possibilities.

“These organisms have been used for centuries to produce food, and they are incredibly efficient at converting carbon into a wide variety of complex molecules, including many that would be almost impossible to produce using a classic host like brewer’s yeast or E. coli,” said Jay Keasling, a senior scientist at Berkeley Lab and a professor at UC Berkeley. “By unlocking koji mold through the development of these tools, we are unlocking the potential of a huge new group of hosts that we can use to make foods, valuable chemicals, energy-dense biofuels, and medicines. It’s a thrilling new avenue for biomanufacturing.”

It’s not just the sustainability benefits that Hill-Maini is seeking. For these products to make the biggest impact, he believes that they should also be truly desirable outside of their wider world benefits. In pursuit of this goal, Hill-Maini and Keasling took their research beyond the laboratory. In a collaboration with Alchemist, a two-Michelin-starred restaurant in Copenhagen, the scientists worked with chefs to explore the culinary potential of Neurospora intermedia, a multicellular fungus traditionally used in Indonesian cuisine. N. intermedia is used to ferment the waste products left over from making other foods, such as tofu, to produce a staple food called oncom. The team discovered that, when grown on starchy rice, the fungi produce an enzyme that liquifies the rice and makes it intensely sweet. “We developed a process with just three ingredients – rice, water, and fungus – to make a beautiful, striking orange-colored porridge,” Hill-Maini stated. “That became a new dish on the tasting menu that utilizes fungal chemistry and color in a dessert. And I think that what it really shows is that there's an opportunity to bridge the laboratory and the kitchen.”

As Hill-Maini's research continues to evolve with support from the Miller Institute at UC Berkeley and the Novo Nordisk Foundation, the fusion of biotechnology and culinary arts promises to revolutionize our relationship with food, offering tantalizing possibilities for both palate and planet.