The Challenge
This is surprising considering plastic makes up ten percent of generated waste.
Items made of polyurethane – one of the most common, and pollutant, industrial plastics used by humans – are particularly destructive to the planet. Polyurethane was created in the 1930s and its use has increased steadily. It is now found in items such as foam insulation, bike seats, garden hoses, shoes, skateboard wheels and more. Its chemical bonds are so strong that it is generally considered non-biodegradable (capable of being decomposed by bacteria or other living organisms). Typically, it has been treated using incineration, which releases harmful gases into the ecosystem. Otherwise it has been disposed of in landfills or the ocean, where, either the sun’s rays or waves very gradually break it into still-harmful microplastic particles that poison marine life when swallowed.
Garden hose (https://en.wikipedia.org/wiki/Garden_hose#/media/File:Garden_hose.jpg)
The Possibilities
A group of researchers from Yale University in the USA may have found a natural combatant to our waste. On a trip to the Amazon, one of the most biologically diverse areas on the planet, the students found a discovered a fungus that eats only polyurethane. Back in the United States tested a sample and isolated the enzymes in the fungus that support its plastic-eating properties. The fungus, pestalotiopsis microspora, is particularly amazing because it can consume polyurethane in an oxygen-free environment. This would seem to make it the perfect combatant to eat the trash at the bottom of a landfill.
“It’s interesting research. I think this approach of bioremediation could be very useful in treating accumulated plastic waste,” says David Schwartzman, professor emeritus of biology at Howard University. He has long studied the ecological properties of fungi and lichens and published several papers on the subject. “Landfills are sources of serious problems. They’re leaking methane as well as other pollutants that get into the groundwater. Some bioremediation may be necessary to deal with the huge mountainous accumulation of these waste.”
The fungus, pestalotiopsis microspora
A landfill in Western Australia
The Risks
Schwartzman says the Yale results are the promising first steps of a much longer scientific examination. “This research is of value, but we should be quite cautious about the application,” he says. “I would be very leery of releasing some organism into [a new] environment. That’s fraught with a lot of potential dangers.”
Schwartzman cites the plastic trash and microplastic particles clogging the oceans. “I’m just imagining a scenario where we say, ‘Let’s get rid of the marine plastics by spraying these fungi’ [into the ocean]. To me, that’s not a viable solution.” He offers an alternate plan: “Collecting the debris and then applying bioremediation to break them down would seem to be a valuable approach.”
Beyond that are potential ‘horror-movie’ effects within the microbe’s structure, says Joel Cohen, head of the Laboratory of Populations at Columbia University and Rockefeller University. He points to one of the fungus’s properties, as described in the Yale paper: its possible ability to take on other species’ genes, and infect other species with its own genes. He asked, “Is there a risk that the process of degradation could spread out of control?” In other words, this incredible plastic-eating enzyme could possibly mutate with other organisms in a landfill and start breaking down materials besides polyurethane—great for authors looking for inspiration for horror-movies, but not great for people living nearby!
Since the study is fairly new, and we know some of the possible risks, how sensible do you think this solution is?
Infographic: http://www.onegreenplanet.org/crushplastic
Sources: http://www.newsweek.com/2014/12/26/plastic-eating-fungi-could-solve-our-garbage-problem-291694.html and http://www.natureworldnews.com/articles/8922/20140908/plastic-eating-fungus-may-solve-worlds-waste-problems.htm
