A coal mine can degrade its local environment. But a fungus may inadvertently help clean up the mine—with its own waste products.

Researchers worked with a fungus called Stilbella aciculosa. As it makes spores, it also produces superoxide. That’s a highly reactive kind of oxygen. When the released superoxide bumps into the mineral manganese in the environment, it makes that mineral much more reactive itself. The pepped-up manganese then grabs and holds a variety of toxic metals and other substances that need to be cleaned up and gotten out of coal mine drainage water.

The research, led by Colleen Hansel of Harvard and the Woods Hole Oceanographic Institution, appears in the Proceedings of the National Academy of Sciences. [Colleen M. Hansel, "Mn(II) oxidation by an ascomycete fungus is linked to superoxide production during asexual reproduction"]

It’s been known that various bacteria and fungi can help in environmental remediation. The new research shows that production of the vital forms of manganese requires that the fungi and bacteria be actively producing superoxide. So creating conditions that encourage the organisms to make the superoxide could be the first step in a pathway by which they help manganese to literally do the dirty work. And make some toxic mine sites a lot cleaner.

—Cynthia Graber

[The above text is a transcript of this podcast.]