Researchers to investigate termite mushrooms as new good food source

Termitomyces​ is the world’s largest edible fungus, with mushrooms that can grow up to a metre in diameter. Its protein content is at the high end among edible mushrooms and higher than chicken.

​It is also ​rich in all nine essential amino acids, and the amino acid composition of the fungus is at the same level as that of meat products and superior to that of plant-based proteins. The catch is, as the name suggests, it needs termites to grow.

Fungal farming termites are of the subfamily Macrotermitinae and live in tropical Africa and Southeast Asia.

Termitomyces​ fungi live in a symbiotic relationship with their termite hosts. In short, termites collect, then munch on 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, in specially designed chambers with carefully regulated temperature and humidity, the termites tend to their fungal farms.

As the termites spread their faeces over the fungus, plant material is broken down, allowing the fungus to grow. Finally, the termites consume the fungus as their only food source.

But these fungi don’t just feed termites. Once a year, they sprout monstrous mushrooms that are collected and sold as an expensive delicacy in Chinese markets and rural areas of Southeast Asia and Africa, where they are an important food source.

“Generally, mushrooms are a good source of protein – and we need sustainable protein alternatives to meat,”​ said Professor Michael Poulsen of the University of Copenhagen’s Department of Biology.

“However, relatively few types of edible mushrooms are on the market today – with the ones that are, primarily grown because they are easy to cultivate, not because of their nutritional and health value.

Here we have a mushroom that has already been naturally optimized to be an ideal food source for animals, meaning that it is also high in qualities as a human food source.”

The task clearly presents several steep challenges. ICRAF researchers remain optimistic, though. Some species have been transported to the lab from Africa to be sequenced, with more on the way. Sequencing multiple species will allow us to better utilize the whole genome. Decoding their genetic information will play an important role in understanding what genes control for important stages of development, such as the emergence of fruiting bodies.

‘We have several unique advantages,’ said Samantha C. Karunaratha, ICRAF mycologist. ‘We have decades of combined experience studying mushrooms in our team. Also, our team is composed of mycologists, ecologists, molecular biologists and entomologists. It is quite rare to find such an interdisciplinary team working on a project like this.’

Each team member brings expertise to a critical aspect of the project and preliminary fieldwork has already begun. Teams have scoured the local wild mushroom markets of Kunming, the capital of Yunnan Province, for Termitomyces species. Specific sites in Yunnan have already been selected and mapped for Termitomyces and soil collection, including Pu’er, Jinghong and Lincang. They cluster at the border with Myanmar across the Upper Mekong River Basin. Data loggers will be used to record conditions in natural habitats.​

ICRAF is no stranger to this tropical region. In the past, researchers have carried out research and training in towns and villages dotting the landscape. Its hills teem with biodiversity and unknown fungi awaiting discovery.

Species from the genus are slow-growing and can take up to two months to be successfully cultured. The project is thus long term in vision. Team members will also be doing focused social-study impact assessments on how to enhance the value chain for mushrooms in the region and connect local producers with socially responsible consumers.

Though past fieldwork has yielded promising results, we continue to know little or even nothing about the vast majority of fungal species populating our planet. Fungi are the ‘dark matter’ of terrestrial life: they seem to play critical roles throughout global ecosystems but we still know little about them. The team intends to use this Termitomyces research to illuminate a small patch of this dark matter.