From penicillin to the blood-cholesterol lowering statins, dozens of revolutionary and life-saving drugs have already been created from chemicals produced by fungi. The organisms in this unique kingdom keep on giving, continually surprising scientists with new potential applications for their many bioactive compounds.
In the latest exciting research, a team from Washington State University, the US Department of Agriculture, and a company called Fungi Perfecta used past insights into the curative properties of mushrooms to create treatments that could help save the world's imperiled honeybee populations – therefore also saving the ecosystems and agricultural industry on which so many other species rely.
Writing in the journal Scientific Reports, the authors explain that the ongoing crisis of colony collapse disorder has been linked to epidemic-level surges of several viruses. (Neonicotinoid pesticides play the other main role by poisoning bees directly or weakening their immune system, thus worsening viral infections.)
Two of the most devastating infections are induced by the deformed wing virus (DWV) and the Lake Sinai virus group (LSV); pathogens that spread rapidly through bee populations via parasitic varroa mites and infected pollen.
“Currently, beekeepers are only able to indirectly control virus levels by using miticides to reduce mite infestation rates in managed honey bees. Overall, this effort has worked with only limited success, given the rapidity with which varroa mites have developed resistance to synthetic miticides,” the authors noted. What the industry really needs, they added, is a non-toxic product that treats the viruses directly. But nothing fitting that description was known to exist.
That is, until famed mycologist Paul Stamets came into the picture. Stamets, the paper’s first author and head of Fungi Perfecta, has worked on numerous projects exploring the medicinal and therapeutic applications of mushrooms for humans.
"He read about viruses hurting bees and called us to explore the use of the extracts on honey bees. After two years, we demonstrated that those anti-viral properties extend to honey bees," lead author Walter Sheppard said in a statement.
Their collaborative investigation kicked off with laboratory-based experiments aimed at identifying which mushroom compounds were best at reducing transmission of the two viruses in caged bees. After the two most promising extracts were found – those from Fomes fomentarius or Ganoderma resinaceum – the team performed field testing on several small outdoor colonies that had been infested with virus-carrying varroa mites.
Within just 12 days, bees fed sugar syrup mixed with one of the two extracts showed dramatically reduced viral loads compared to those fed plain sugar syrup. Using PCR analysis, the researchers determined that the F. fomentarius extract treatment led to deformed wing virus levels 44 times lower than control, and Lake Sinai virus levels 88 times lower. G. resinaceum extract also lowered DWV infection to levels nearly 80-fold lower than controls, but then truly stole the show with its activity against LSV: treated colonies had 45,000-fold lower viral levels.
"We aren't sure if the mycelium is boosting the bees' immune system or actually fighting the viruses," Sheppard said. In addition to answering that question, the team's next step is to develop protocols on how to utilize the extract to its full potential.
"Time is running out for bee populations and the safety and security of the world's food supply hinges on our ability to find means to improve pollinator health."
Anticipating the large demand from beekeepers eager to protect their charges, Stamets added that his company is ramping up production of the extracts as quickly as possible.
