Mycoremediation in Ecuador

They don't have embedding so I wouldn't normally bother pointing you to this, but Time has a video report on using mycoremediation to clean up oil spills in Ecuador. They didn't say the variety, but they look like Oyster mushrooms and I'm so excited that this technique is finally getting wider use.

If you read from Paul Stamets' Mycelium Running, a book about how mushrooms can save the world (excerpt here), describes the first major pilot of such a project with the Washington State Department of Transportation (WSDOT). A species of Oyster mushroom, Pleurotus ostreatus, was used to successfully decontaminate a large pile of diesel oil saturated dirt that was virtually incapable of supporting life.

However, the Oyster mushrooms, with their mycelial spawn spread in layered sheets, came from a strain that had been taught in a controlled environment to digest diesel fuel and they did so in the soil samples. (Though the mycelia would be spread through spawn-saturated wood chips or grain medium, strategically placed. Not, as they probably show for dramatic effect in the video, by placing mushroom fruiting bodies on top of contaminated soil. That would serve no purpose.)

Mushrooms, as the only type of multicellular organisms that can digest cellulose and lignin (all higher animals who do this carry bacteria in their guts to perform the actual digestion), have enzymes that can be adapted to break down almost any complex hydrocarbon. It turns out to be relatively easy to teach them to 'eat' petroleum compounds, just big hydrocarbon chains that are similar to the lignin compounds that give wood its hardness, and turn them into benign organic molecules. Further research described in Mycelium Running demonstrated that mycelial digestion could even denature compounds like VX and sarin chemical weapons.

As the video states, they wouldn't be able to do this in thick spills or water, so as much of the oil as possible needs to be hauled away after a spill. They didn't elaborate, but from the images I suspect the reason is that the mycelium need oxygen. A saturated, oxygen-free environment, such as when you've got basically large puddles of oil, there's no way to get air to the mycelial strands. In relatively dry conditions, there would be pockets of air trapped between soil particles and some circulation possible.

There are water-borne fungi, but it's a diverse family of organisms and those species are very different from the ones that digest wood on forest floors the world over.

Anyway, the potential for using fungi to reclaim soil and begin a cycle of life has a long history on our planet. Fungi were likely the enablers of the first land plants, and probably began creating soil out of mineral fragments as partners with algae in lichen form - crumbling rock and turning that dead rock dust into a life support medium for innumerable organisms. Also, as an integral inhabitant of healthy, typical soils, fungi are important to maintaining maximum species diversity.

Though while global warming is enabling pathogenic fungi to threaten the extinction of a third of all amphibian species, a host of factors likely including pollution and acid rain have reduced fungal diversity by 50 percent in some parts of Europe, where scientific monitoring of even such difficult to detect species would be more intense. And every time a plow blade cuts through agricultural land, it disrupts any mycelial nets that have managed to colonize the area, so while they may be unlamented, their diversity is still reduced. Very sad state of affairs for such an old and respectable kingdom of organisms.

It's nice to see fungi being used as they ought to be, to create healthy soil where nothing could live before.

(Photo credit: benketaro on Flickr.)