The same fungi that decompose fallen logs in forests can break down antidepressants in treated sewage — before that sewage gets spread on the fields where food grows.

That’s the finding from Johns Hopkins researchers, who showed that two common mushroom species, oyster mushrooms (Pleurotus ostreatus) and turkey tail (Trametes versicolor), can degrade psychoactive pharmaceuticals embedded in biosolids — the nutrient-rich sludge left after wastewater treatment. The pipeline is straightforward and unsettling: people take medications, excrete trace compounds, those compounds survive conventional treatment, and the resulting sludge gets applied to farmland as fertilizer across the United States. Pathogens and metals are stripped out effectively, but complex organic chemicals like the antidepressants citalopram and trazodone pass through largely intact.

In the study, published in ACS Environmental Au, the researchers spiked municipal biosolids with nine psychoactive drugs and let the fungi grow directly on the material for up to 60 days. Each species degraded eight of the nine compounds, with removal rates between 50% and near-complete elimination. The oyster mushroom was the standout, removing more than 90% of several antidepressants.

“Even small concentrations of these compounds can have psychological effects when consumed, which is why they have become contaminants of concern,” said Kate Burgener, the study’s lead author and a PhD student at Johns Hopkins.

The fungi aren’t just absorbing the drugs — they’re chemically dismantling them. The team identified over 40 transformation products, and an EPA hazard assessment predicted most were less toxic than the original compounds.

What makes the approach appealing is its simplicity. White-rot fungi release nonspecific enzymes capable of breaking apart diverse complex molecules, and both species tested are cheap and widely available. The researchers call the strategy “mycoaugmentation” — adding fungi to biosolids before land application — a low-energy, low-infrastructure intervention that could slot into existing waste management without major retooling.

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