Mushroom properties in the degradation of plastics and wastes


It may sound incredible, but also plastic products that have been thought to be degraded in nature for hundreds of years can be degraded much faster with the help of enzymes produced by microorganisms, as well as well-known edible, even health-beneficial, fungi.

These days the environmental burden of waste from plastic products forces us to think about how to destroy them in a way, which would be environmentally friendly. In addition to recycling, an alternative is available in the form of special species of mushrooms, which under certain conditions are capable of spreading petroleum products or bio-waste. It is well known that the thermophilic ascomycete Myceliophthora thermophila at high temperatures efficiently decomposes cellulose, moreover it is increasingly spoken of in connection with the production of biofuels that would replace the currently used oil fuels. This fungus can quickly decompose biomass even in the middle of warm compost, where many other organisms, that would compete with this mushroom are not able to survive. Additionally, some mushroom isolates of this genus have been shown to cause disruption of the plastics structure through the laccase enzyme.

Microscopic fungi Trichoderma viride and Aspergillus nomius were isolated from the soil to test their ability to decompose low density polyethylene (LDPE). It has been shown that some isolates have been able to break the surface of the plastic and have proven to reduce the weight of the polyethylene used. Under the electron microscope it was possible to observe the grooves and roughness caused by fungus activity. Even among well-known edible mushrooms, we find species capable of contributing to the degradation of plastics. For example, the lung oyster - Pleurotus pulmonarius, growing on living trees, has been able to reduce the weight of LDPE powder to almost ten percent. Even better results were seen in a tropical species called Pleurotus tuber-regium.

Environmental pollution is also the contamination of soil with liquid petroleum products. Many experiments have demonstrated the ability of fungi to effectively absorb these substances from the soil and contribute to recultivation. It is also known that mushrooms can absorb heavy metals and radioactive elements from contaminated soil. On the walls of the Chernobyl nuclear reactor a fungus was observed. This environment was obviously suitable for it. Increased amount of radiocaesium content was found in the vast majority of mushroom specimens from around the Fukushima nuclear power plant. Fungi from heavily contaminated areas can hardly be recommended for collection and consumption, but thanks to their unique properties, the accumulation of pollutants from the environment has a great potential for land recultivation.