Just in time for Halloween, Korean scientists say they’ve found a better way to grow an insect-killing fungus in the lab. Their work could make it easier to study these fungi, which is important because they and the chemicals they produce may actually have medicinal uses for humans, frightening as they are.
Mushrooms are known as Cordyceps. Members of this genus, as well as a related but distinct genus called Ophiocordyceps, are parasitic, usually feeding on insects and other arthropods. These fungi often invade and kill their hosts, but not before using them as fuel to grow their fruiting bodies (technically that’s the part of the fungi we call the fungus) and releasing new infectious spores into the world to start the process. once again. Some members of Ophiocordyceps are also known forzombify» their ant hosts by manipulating their behavior before death to ensure their optimal survival.
As horrible as their way of life is, some members of Cordyceps are considered food in parts of Asia. They also have been used in traditional Chinese medicine and more recently are sold as supplements (supplements of any kind, it should be noted, have little quality control and are not necessarily harmless). Summerearly research has suggested that Cordyceps produce chemicals that could have health benefits, specifically a compound called cordycepin. Some studies have indicated, for example, that cordycepin may have antiviral or anticancer properties.
Much of this research comes from animal or laboratory studies, which means that much more evidence in humans will be needed to confirm potential benefits. These experiments and any eventual widespread use of Cordyceps will also require having enough mushrooms or their compounds, and that is a challenge. Although these mushrooms are found all over the world, they are difficult to find and harvest in the wild. There are now ways to grow them in the lab, but current methods only produce small amounts of healthy plants. Cordyceps or cordycepin, which makes them difficult to develop.
Researchers at National Chungbuk University have tried to improve on these methods, which typically use brown rice as the growth medium. They hypothesized that these fungi would grow better on richer protein sources, namely insects. They also guessed that their diet would affect the size of the mushrooms and the amount of cordycepin they produced, so they tested different types of insects. These insect nurseries were kept growing for two months before the researchers harvested the Cordyceps. The team’s findings published Wednesday at Frontiers in microbiologysuggests that their insect theory was just for the money.
“Cordyceps grown on edible insects contained about 100 times more cordycepin than Cordyceps on brown rice,” said study author Mi Kyeong Lee, a professor at Chungbuk, in a statement of Borders.
As expected, however, there were differences in how the insects’ food affected their growth. Fungi were more abundant when feeding on mealworms and silkworm pupae, for example. But they actually produced the most cordycepin when they fed on Japanese rhinoceros beetles. The team’s work also indicates that it was the insects’ fat content, not their protein, that predicted the amount of cordycepin produced by the fungi. The rhinoceros beetles were particularly full of a type of fat called oleic acid, and once the team introduced oleic acid into a low-fat insect food, the Cordyceps‘ Cordycepin production also increased.
“The cultivation method of Cordyceps suggested in this study will enable the production of cordycepin more efficiently and economically,” Lee said.
Although these scientists found an improved method of growing Cordyceps in the lab, you probably shouldn’t expect mass production just yet. The authors note that producing insects on an industrial scale is not easy either. So if these bizarre mushrooms turn out to be medically useful, there will be more challenges in developing them for mass use. That said, there is at least one research team at Oxford University actively studying a modified version of cordycepin as an anticancer drug in early human trials.