Breakthrough: Fungi May Hold the Key to Biodegrading Polypropylene
By Strategic Research Institute on Jun 13, 2023 08:00 am
Polypropylene, a ubiquitous plastic found in a wide range of products, has long posed a recycling conundrum. Despite accounting for approximately 28 percent of the world's plastic waste, only a mere 1 percent of polypropylene is currently recycled. However, researchers at the University of Sydney may have discovered a breakthrough in the form of fungi. Their study, published in npj: Materials Degradation, demonstrates how common strains of fungi can effectively biodegrade polypropylene in laboratory conditions.
In the experiment, Aspergillus terreus and Engyodontium album, fungi commonly found in soil and plants, were employed to break down polypropylene. The plastic was pre-treated with UV light or heat before the fungi were applied, resulting in a reduction of plastic mass by 21 percent over 30 days and 25-27 percent over 90 days of incubation.
Amira Farzana Samat, the lead author of the study, highlights the pressing issue of polypropylene's low recycling rate. With a recycling rate of just 1 percent, polypropylene significantly contributes to plastic waste and global pollution. The researchers' method offers hope for mitigating the environmental impact of plastic pollution and gaining insights into natural biodegradation processes.
Plastic pollution is undeniably one of the most critical waste challenges of our time. The overwhelming majority of plastic is inadequately recycled, leading to its accumulation in oceans, rivers, and landfills. Shockingly, an estimated 109 million tonnes of plastic pollution currently resides in rivers, with 30 million tonnes saturating our oceans, projected to exceed the total mass of fish. These alarming figures emphasize the urgency of addressing plastic waste.
The rarity of polypropylene recycling can be attributed to its short lifespan as a packaging material and its susceptibility to contamination by other materials and plastics. Overcoming these challenges requires new recycling methods with minimal environmental impact. Professor Ali Abbas, PhD supervisor to Amira Farzana Samat, underscores the need for a comprehensive understanding of plastics' degradation under environmental conditions, particularly the role of biological processes offered by fungi and microorganisms.
Professor Dee Carter, an expert in mycology and co-author of the study, explains that fungi possess remarkable versatility in breaking down various substrates. Their enzymatic activity enables the breakdown of complex materials into simpler molecules that fungal cells can absorb. Although fungi have evolved to decompose woody materials, their capabilities can be harnessed to address other substrates, including plastics.
The research involved treating polypropylene with ultraviolet light, heat, or Fenton's reagent, an acidic solution used to oxidize contaminants. The fungi were then applied to the treated plastic in petri dishes, and microscopy techniques confirmed the biodeterioration. While the exact bio-chemical processes behind the plastic's degradation remain to be determined, further research is planned to elucidate these mechanisms.
Excitingly, the research team has already isolated microorganisms from the marine environment and employed similar techniques to degrade marine plastic waste, yielding even higher degradation rates. This development opens new avenues for improving the degradation process and holds promise for future advancements in sustainable plastic management.