Marine Fungus Consumes Plastic Waste

It’s evident that we have a significant plastic waste problem, but various initiatives aim to curb it while also addressing the existing pollution. Nature is also stepping in, as scientists have discovered a marine fungus that plays a crucial role in consuming plastic.

The fungus, Parengyodontium album, emerged among other marine organisms on plastic waste samples collected from the North Pacific Garbage Patch in December 2019 during the Ocean Cleanup’s North Pacific Mission 3.

Identifying a Polyethylene-Degrading Marine Fungus

Marine biologists from the Royal Netherlands Institute for Sea Research, in collaboration with Utrecht University and institutes in Paris, Copenhagen, and Switzerland, identified and isolated the fungus. In the lab, they grew the fungus and discovered it could break down polyethylene, one of the most common plastics used in packaging film, grocery bags, bottles, toys, and housewares.

While previous studies have identified bacteria and enzymes that can degrade plastic waste, plastic-eating marine fungi are rare. Parengyodontium album is now the fourth known marine fungus with this ability. The significance of this discovery lies in the scientists’ ability to quantify the rate of plastic degradation by the fungus.

Polyethylene Degradation Rate under UV Light

Laboratory experiments show that the fungus can break down and utilize polyethylene (PE) marine waste exposed to ultraviolet (UV) light as an energy source, at a rate of 0.044% per day.

“In our lab experiments, we observed that P. album only decomposed PE that had been exposed to UV light for a brief period.”

“This implies that in the ocean, the fungus can only degrade plastic that has initially floated near the surface,” explained study lead author Annika Vaksmaa.

“While previous knowledge suggested that UV light mechanically breaks down plastic, our findings demonstrate its role in facilitating the biological degradation of plastic by marine fungi.”

Fungus’s Limited Metabolism of Polyethylene

One potential drawback is that the fungus appears to metabolize only a small portion of the carbon present in the polyethylene, primarily converting it into carbon dioxide and excreting the greenhouse gas.

However, researchers do not perceive the amount produced—comparable to the minimal quantity emitted by humans during respiration—as posing a significant new environmental concern.

Vaksmaa proposes that other unidentified fungi are likely participating in the degradation of plastics both on the ocean’s surface and beneath it.

“Marine fungi have the capability to decompose complex carbon-based materials,” she explained. “Given the abundance of marine fungi, it’s probable that, in addition to the four species identified thus far, other species also play a role in plastic degradation.”

Read the original article on: New Atlas

Read more: A New Method Can Make Plastics More Environmentally Friendly