Fungi have yielded many compounds with medicinal qualities. A newly discovered compound, derived from a rare fungus, promises to aid the fight against antibiotic resistance.

The compound was discovered by coaxing deactivated genes in the fungus Doratomyces microsporus back to life.

Many of the therapeutic compounds discovered in fungi are constantly produced. A fungus may only periodically produce a compound. Production may cease for long periods of time.

"Fungi can even deactivate the respective parts of their genome if a metabolite is not needed anymore. These compounds can't be detected any longer and are classified as cryptic compounds," Christoph Zutz, a food scientist at the Vetmeduni Vienna, said in a news release.

For this reason, scientists hypothesize that many potentially valuable compounds may lie dormant, the code for their synthesis hiding among inactive genes.

By introducing valproic acid to Doratomyces microsporus, scientists were able to trigger the production of several previously dormant, or "cryptic," antibiotic and antimicrobial compounds.

One compound, called cyclo-(L-proline-L-methionine), or cPM, proved effective at fighting both normal strains of Staphylococcus aureus pathogens and strains that have built up resistance to antibiotics. The compound was previously discovered in a marine sponge in the frigid coastal waters of Antarctica.

When cPM was used together with ampicillin to battle two strains of ampicillin-resistant bacteria, the pathogens were killed.

"The resistance was demonstrably reduced, even at a lower dose of ampicillin than usually," said lead researcher Kathrin Rychli.

The researchers, who published their latest findings in the journal Frontiers in Microbiology, say they will continue to search for other cryptic and novel antibiotic compounds using similar methods.

"Valproic acid is not the only way to gain active compounds from fungi or other microorganisms," explained Joseph Strauss, a researcher from the University of Natural Resources and Life Sciences in Vienna. "You can also make bacteria and fungi grow together. This also leads to a natural stimulus."