You may have read about it. Cordyceps fungi that turn insects into mindless zombies. A mushroom sprouts from the body of the undead insect, spreading fungal spores in search of new victims. Creepy, isn't it?
Although the fungus kills insects, this is not the case in humans. On the contrary. Of the hundreds of species included in the genus Cordyceps, some make the medicinal substance cordicepine. For thousands of years, these mushrooms have been used as medication or supplements. This is because the substance has antiviral properties. In addition, cordicepine is a cytotoxin. That means it poisons specific body cells and can therefore inhibit tumour growth. Not so scary at all, then.
Beetle as food?
Unfortunately, the medicinal effects seem to disappear when the fungus is grown in a laboratory. South Korean researchers have found a way to change this. Cordyceps is now grown on grains or rice, but these contain not enough protein. The research team therefore experimented with edible insects. This showed that the fungus grows best on mealworms and silkworm pupae, but by far the most cordicepine was produced on Japanese rhinoceros beetles. Up to a hundred times more than on brown rice! The researchers suspect this is because of the high fat content in the beetle. What turns out? Oleic and unsaturated fatty acids are essential for cordicepine production, and not proteins as previously suspected.
The perfect diet
These new findings allow the cultivation of Cordyceps, and the production of cordycepin, to be carried out on a larger scale. Unfortunately, the process is still not efficient enough for global production. More research is needed to find the very best cultivation method. Perhaps a combination of all kinds of insects is the right diet. And who knows, maybe the zombie fungus will soon help us against all kinds of ailments and diseases!
Turk, Ayman, et al. "Cordyceps mushroom with increased cordycepin content by the cultivation on edible insects." Frontiers in Microbiology 13 (2022).