Plastic pollution has become one of the most pressing environmental challenges of our time. With millions of tonnes of plastic waste accumulating in oceans, land and landfills every year, the search for sustainable solutions is more urgent than ever.
Faced with this problem, a surprising discovery has attracted the attention of scientists and the public: certain mushrooms have the ability to “eat” plastic. This article explores this potential game-changing solution, detailing current scientific research, challenges and possible future applications.
Src : https://www.actu-environnement.com/ae/news/deux-nouvelles-etudes-prence-plastique-oceans-31174.php4
1. The Devastating Impact of Plastic on the Environment
Global plastic production has exceeded 400 million tonnes per year, and the majority of these plastics end up as waste after often very brief use.
Plastics, due to their chemical composition, take centuries to decompose naturally, leading to a massive accumulation of plastic waste in the environment. The oceans, for example, today contain more than 150 million tons of plastic, creating "islands" of floating trash, such as the infamous "Great Pacific Garbage Patch."
Plastics do not completely degrade in nature; they fragment into microplastics, tiny particles that infiltrate ecosystems and the food chain.
These microplastics have been found in fish, shellfish and even drinking water. They pose a danger not only to wildlife, which may ingest them by mistake, but also to human health.
2. Mushrooms: Powerful Natural Decomposers
Fungi play a crucial role in natural ecosystems as decomposers. Unlike plants, which use photosynthesis, fungi break down organic matter using enzymes they secrete into their environment. This process recycles essential nutrients into the soil. But recently, researchers have discovered that certain fungi are capable of breaking down much tougher materials, including plastic. (Khan, S., et al. (2017). “Biodegradation of Polyester Polyurethane by Aspergillus tubingensis.” Environmental Pollution, 225, 469-480)
These decomposer fungi produce enzymes such as peroxidases and laccases, which can break down the long polymer chains found in plastics. This process is similar to the one they use to break down complex materials like wood.
This unique ability has generated considerable interest in the scientific community, which seeks to harness these fungi to process plastic waste.
3. Plastic-Eating Mushrooms: A Revolutionary Solution?
Two species of fungi have particularly attracted attention for their ability to break down plastic: Pestalotiopsis microspora and Aspergillus tubingensis.
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Pestalotiopsis microspora: Originally discovered in the rainforest of Ecuador, this fungus has the unique ability to break down polyurethane, a type of plastic widely used in products ranging from clothes to refrigerators. Yale University researchers, who conducted studies on Pestalotiopsis microspora, discovered that this fungus could not only decompose polyurethane in the absence of oxygen, but could also convert it to biomass, making it a potential solution for anaerobic landfills.
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Aspergillus tubingensis: Discovered in a dump site in Pakistan, Aspergillus tubingensis was revealed be able to break down polyester in just a few weeks. This fungus works by secreting enzymes that break the chemical bonds in plastic, thus facilitating its degradation. Research by scientists at the Kunming Institute of Botany showed that this process could be accelerated by adjusting environmental conditions, such as pH and temperature.
4. How Does the Plastic Decomposition Process by Fungi Work?
The process of plastic decomposition by fungi is based on enzymatic activity. Fungi secrete enzymes such as hydrolases, which break down plastic polymers into smaller monomers. Here are the main steps of the process:
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Hydrolysis: Fungal enzymes attack ester bonds in plastic polymers, initiating the breakage of long, complex chains into smaller, soluble units.
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Biodegradation: Once polymers are broken down into monomers, fungi use them as a source of carbon and energy. This process not only breaks down plastic, but also converts it into biomass and other organic compounds.
Research has shown that certain species of mushrooms can reduce the weight of plastic waste by 40-60% in just a few weeks. However, the rate of decomposition depends on many factors, such as the type of plastic, enzyme concentration, and environmental conditions like temperature and humidity.
5. Practical Applications and Future Potential
The use of plastic-eating mushrooms has enormous potential for waste management. Among the practical applications, we can cite:
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Landfill bioremediation: Mushrooms could be used to treat plastic waste in landfills, reducing their volume and the risk of environmental contamination.
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Wastewater treatment systems: Fungi could be integrated into wastewater treatment systems to degrade microplastics, thereby reducing plastic pollution in waterways. water and oceans.
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Sustainable manufacturing: By harnessing fungi to produce plastic-degrading enzymes, it may be possible to develop plastic materials that are more easily biodegradable.
Biotech startups such as Biohm in the UK and Fungi Mutarium in Austria are already working on commercial applications of fungi for plastic degradation and sustainable materials development. However, there are still many challenges to overcome for large-scale implementation.
6. The Challenges and Limitations of Using Plastic-Eating Mushrooms
Although promising, plastic-eating fungi present significant limitations and challenges:
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Specific growing conditions: Fungi require specific growing conditions, such as optimal pH and humidity levels, which can be difficult to reproduce on a large scale. ladder.
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Variable decomposition rate: Not all types of plastics are as easily broken down by fungi. For example, high-density plastics like high-density polyethylene (HDPE) are stronger than low-density plastics.
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Potential environmental impacts: Introducing decomposer fungi into uncontrolled environments could have unforeseen effects on local ecosystems.
Despite these challenges, continued research and technological improvements could help overcome these obstacles. Mushrooms offer a potential biological solution to the global plastics crisis, but they should only be seen as part of a broader, integrated approach to plastic waste management.
7. Conclusion: Mushrooms, a Hope for a Plastic-Free Future?
Plastic-eating mushrooms represent an innovative and natural approach to addressing the global plastic waste crisis. By breaking down complex plastic polymers into their basic components, these fungi could offer a sustainable solution for waste management and bioremediation. However, their large-scale use requires further research, testing and technological development.
It is essential to continue exploring natural solutions like mushrooms while integrating plastic reduction, reuse and recycling strategies. With increased collaboration between scientists, governments, and businesses, it is possible to hope for a future where plastics are no longer a burden on our planet.
