Just in time for Halloween, scientists in Korea say they’ve found a better way to grow an insecticidal fungus in the lab. Their work could make these fungi easier to study, which is important since they and the chemicals they produce could actually have medicinal benefits for humans, creepy as they are.
The fungus is known as Cordyceps. Members of this genus, along with a related but distinct genus called ophiocordyceps, are parasitic and usually feed on insects and other arthropods. These fungi invade their hosts and often kill them, but not before using them as fuel to grow their fruiting bodies (technically this is the part of fungi we call fungi) and releasing new infectious spores into the world, to start the process all over again. Some members of Ophiocordyceps are also known for “zombifying” their ant hosts by manipulating their pre-death behavior to ensure their optimal survival.
As frightening as their way of life is, some members of Cordyceps are considered food in parts of Asia. They have that too have been used in traditional Chinese medicine and are more recently sold as dietary supplements (dietary supplements of any kind, it should be noted that they little quality control and are not necessarily harmless). And Zarly research has suggested that Cordyceps produce chemicals that might have beneficial health effects, specifically a compound called cordycepin. For example, some studies have shown that cordycepin may have antiviral or anticancer properties.
However, most of this research comes from animal or laboratory studies, which means a lot more evidence is needed in humans to confirm potential benefits. These experiments and any eventual widespread use of Cordyceps also requires an adequate supply of the fungi 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 cultivate them in the lab, but current methods yield only small amounts of healthy Cordyceps or cordycepin, which makes them difficult to enlarge.
Researchers from Chungbuk National University tried to improve on these methods, which typically use brown rice as a growing medium. They theorized that these fungi would grow better on richer sources of protein—namely insects. They also suspected their diet would affect how big the fungi got and how much cordycepin they produced, so they tested different types of insects. These insect nurseries were allowed to continue growing for two months before the researchers harvested them Cordyceps. The results of the team released Wednesday in frontiers in microbiologysuggests that their insect theory was spot on.
“Cordyceps Grown on edible insects, by comparison, contained about 100 times more cordycepin Cordyceps on brown rice,” said study author Mi Kyeong Lee, a professor at Chungbuk, in a expression of borders.
However, as expected, there were differences in how insect food affected their growth. The fungi were most numerous when feeding on mealworms and silkworm pupae, for example. But they actually produced the most cordycepin when they fed on Japanese rhino beetles. The team’s work also shows that it was the insects’ fat content, not their protein, that predicted how much cordycepin the fungi produced. The rhino beetles were particularly high in a type of fat called oleic acid, and when the team introduced oleic acid to a low-fat insect diet, the Cordyceps‘ Cordycepin production also increased.
“The cultivation method of Cordyceps proposed in this study will enable the production of cordycepin more effectively and economically,” Lee said.
While these scientists may have found an improved cultivation method Cordyceps In the lab, you probably shouldn’t expect mass production just yet. The authors note that it is also not easy to produce insects on an industrial scale. So, should these crazy mushrooms prove to have medicinal value, further challenges lie ahead in developing them for mass use. However, at least one research team at Oxford University is actively investigating a modified version of cordycepin as a cancer drug in early human trials.