A “Mouldy” Meat Alternative Harnesses Ancient Fermenting Science

A “Mouldy” Meat Alternative Harnesses Ancient Fermenting Science

The people who develop meat alternatives have been thinking further and further outside the box recently. But until encountering this week’s topic, I hadn’t yet thought of mould – yes, the stuff that usually makes you throw out a piece of meat – as the building block for a new kind of protein.

Scientists from Lawrence Berkeley National Laboratory have gene-edited Aspergillus oryzae, a multi-celled fungus also known as koji mould, to prompt it to form itself into a delicious, burger-like patty. Koji mould has been used for centuries to ferment such tasty, umami-rich foods as soy sauce and miso. It seemed a logical, if meticulous, process to turn it into the main course!

“To begin, (project leader and bioengineer Vayu) Hill-Maini focused on boosting the mould’s production of heme – an iron-based molecule which is found in many lifeforms but is most abundant in animal tissue, giving meat its colour and distinctive flavour. (A synthetically produced plant-derived heme is also what gives the Impossible Burger its meat-duping properties.) Next, the team punched up production of ergothioneine, an antioxidant only found in fungi that is associated with cardiovascular health benefits. After these changes, the once-white fungi grew red. […]

Hill-Maini’s next objective is to make the fungi even more appealing by tuning the genes that control the mould’s texture. “We think that there’s a lot of room to explore texture by varying the fibre-like morphology of the cells. So, we might be able to program the structure of the lot fibres 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.’”

The photos included in the source article show a juicy, Maillard-reaction-bedecked patty that I actually wouldn’t mind trying on a bun with lettuce, tomatoes, and a slathering of our BBQ sauce! Creating something satisfying enough to be the centrepiece of a meal from an ultra-sustainable and -replicatable mould is a win for both our taste buds and our planet. I’m looking forward to seeing these burgers at the shops – and trying a couple on the grill myself.