Termites have been cultivating and eating them for 30 million years. This incredible mushroom has more protein than chicken, soy and corn but has yet to be grown by humans. By mimicking termites, scientists from the University of Copenhagen will study whether these fungi can become a sustainable food source for humans.
Termites are more than just pests. In fact, termites in Africa and Asia have been advanced mushroom growers for 30 million years. As a very unique thing in nature, they only cultivate mushrooms for food. And through evolution, they have optimized their fungi to become an ideal food source.
“Mushrooms are generally a good source of protein – and we need sustainable protein alternatives to meat. However, there are relatively few edible mushroom varieties on the market today – primarily because of their ease of cultivation, not their nutritional and health value. Here we have a fungus that has already been naturally optimized as an ideal food source for animals, which means that it is also of high quality as a human food source,” says Professor Michael Poulsen from the University of Copenhagen’s Department of Biology.
Poulsen and a group of fellow researchers will now set out to determine what it takes to get Termitomyces fungi into production as a human food source, that is, without termite intervention. For this, Professor Poulsen has just received a grant from the Independent Research Fund Denmark.
Grow mushrooms with their feces
Mushroom farming termites belong to the subfamily Macrotermitinae and live in tropical Africa and Southeast Asia.
Termitomyces is the world’s largest edible fungus, with mushrooms that can reach up to a meter in diameter.
The protein content of Termitomyces is on the higher end among edible mushrooms and higher than chicken.
Termitomyces is rich in all nine essential amino acids, and the amino acid composition of the fungus is superior on the same level as that of meat products and that of vegetable proteins.
The global sales of edible mushrooms was US$16.7 billion (2020) and is expected to reach US$20.4 billion by 2025.
Termitomyces fungi live in a symbiotic relationship with their termite hosts. In short, termites collect and then eat dead plant materials such as leaves, wood, and grass, which pass through their intestines in a semi-digested state before being excreted into the termite nest.
There the termites cultivate their mushroom farms in specially designed chambers with carefully regulated temperature and humidity. When the termites spread their droppings over the fungus, plant matter is broken down, allowing the fungus to grow. Eventually, the termites consume the fungus as their sole food source.
But these fungi don’t just feed on termites. Once a year they sprout monstrous mushrooms that are collected and sold as an expensive delicacy in Chinese markets and in rural areas of Southeast Asia and Africa, where they are an important food source. Which makes perfect sense, as Poulsen explains:
“These mushrooms contain more protein than chicken and plants like soy, corn and peas, have a better amino acid composition and also contain a variety of healthy vitamins. Nutritionally, they’re on the high end – and they even taste good. However, since they cannot currently be cultivated without termite hosts, their availability as a human food source is limited.”
Restore conditions to termite nests
The research project will go two ways:
“Right now we can grow mushroom mycelium on a small scale, but without mushrooms. We’ll see if we can scale up the production to make it profitable. The idea is to cultivate the mushrooms on leftover plant substrates. In Denmark, that could be wood chips or straw that would otherwise be burned. Here we may be able to convert some of this material into fungal biomass for human or agricultural consumption,” explains Michael Poulsen.
At the same time, the researchers will investigate what is required to promote fungal growth.
“The other avenue we’re going to take is to understand the natural processes involved in the formation of these fungi. We will try to replicate the same conditions as in a termite colony – in terms of temperature, humidity, CO2, plant biomass composition, etc. At the same time we will look at which genes are expressed in fungi and produces. If we better understand their biology, we will be better equipped to mimic the conditions fungi require in the laboratory,” says Michael Poulsen.
Professor Poulsen points out that the production of Termitomyces fungi primarily as an alternative source of protein would have high market value. Additionally, large-scale production could have a positive impact on local economies in parts of the world where these fungi already grow naturally but their collection is limited to termite colonies.