Mushrooms Found in Sri Lanka That Break Down Plastic

Researchers from the University of Kelaniya and the University of Peradeniya in Sri Lanka have discovered new species of mushrooms capable of decomposing polyethylene, the plastic used in making bags, bottles, food wraps, and food containers. This discovery was reported by ArsTechnica.

The key feature of these mushrooms is their ability to break down solid wood. Scientists found these mushroom species during their study of dead deciduous trees containing lignin polymer, which gives strength to wood.

During the experiment, researchers collected samples of wood-decomposing mushrooms and brought them to the laboratory for further study. The mushrooms were given both wood fragments and polyethylene to assess their ability to digest plastic. The study also investigated how each mushroom species produces enzymes that aid in lignin degradation. The effectiveness of the process was evaluated by comparing changes in material weight before and after exposure to the mushrooms.

Over a span of 45 days, the wood lost between 1% and almost 36% of its weight. This weight loss occurred because the mushrooms broke down lignin and cellulose into products that released carbon dioxide. Plastic also lost nearly half of its mass, transforming into simpler molecules due to the enzymes produced by the mushrooms. During the degradation of polyethylene, it became more brittle and lost its water-repellent properties.

Researchers also tested whether the mushrooms would break down plastic in the absence of wood, as they hypothesized that their digestive enzymes might only be activated in the presence of wood. However, the experiment revealed that all mushroom species actively degrade polyethylene even without wood present.

"The most striking feature of the experiment was that all samples demonstrated enhanced polyethylene degradation in the absence of wood, compared to its presence," the researchers stated in the same study.

These mushrooms require carbon for survival. While wood serves as their primary source of carbon, when unavailable, polyethylene became an alternative. The degradation of larger amounts of plastic in the absence of wood indicated their metabolic adaptation and dietary shift when wood was absent.

In the future, these mushrooms might be utilized for breaking down plastic waste on a larger scale, but developing more extensive operations involving the use of mushrooms for plastic cleanup will require time.