No Ifs, Ands, or Butts About It: Solving the Cigarette Waste Problem with Mushrooms

Every year, 4.5 trillion cigarette butts are littered worldwide, with around 9 billion coming from Australia, according to the nonprofit Australian environmentalist group, No More Butts. These cigarette butts pose a threat to the environment since they are not biodegradable and are full of chemicals that are harmful to our environment and contribute to climate change. Plus, they’re the most abundant plastic waste in the world. Fortunately, Australian researchers have found a way to train mushrooms to consume and decompose cigarette butts. This new technology has the potential to not only reduce the butt’s waste but also transform them into recyclable material.

A sustainable approach to cigarette butt waste

Fungi Solutions is a Melbourne-based company dedicated to finding innovative and sustainable solutions to the problem of non-biodegradable waste in landfills. The company aims to recover resources from these waste streams and transform them into new sustainable products using their unique mushroom technology. They have been working to develop their mushroom technology for several years, focusing on using oyster mushrooms to decompose waste. Through their research and experimentation, the company has even created their own species of mushroom capable of feeding on cigarette butts which are notoriously difficult to dispose of naturally. 

The company’s breakthrough mushroom technology has caught the attention of Sustainability Victoria, which has agreed to sponsor Fungi Solutions’ efforts to perfect their methods of disposing cigarette waste. This support from Sustainability Victoria is a major step forward for Fungi Solutions, as it will allow the company to expand its research and development efforts to scale up its operations.

No More Butts and Fungi Solutions have collaborated to launch the CigCycle program,  a research project aimed at determining the efficacy of using mushrooms to break down cigarette butts and whether the method could be a viable recycling program in the future. The CigCycle program plans to remove 1.2 million cigarettes from landfills over the course of the trial and will involve the collection of cigarettes from around eighty Melbourne businesses. Though the results are not perfect yet, the oyster mushrooms being used by Fungi Solutions are getting closer and closer to becoming a large-scale solution for disposing of cigarette butts.

Mycoremediation as a plastic waste solution

This isn’t the first time fungi have been used to break down inorganic matter. There has been increasing interest in mycoremediation, which is a way to use mushrooms and their enzymes to break down hazardous waste and non-biodegradable matter. Many different kinds of mushrooms are able to break down plastics, and there have been several species that have been discovered over the past few years that can do so. Recently, Australian scientists have discovered that two types of common soil fungi could be used to break down polypropylene in less than five months. Polypropylene is a type of plastic used in disposable water bottles, some plastic bags, bottle caps, fabrics, and more. The discovery of fungi like these gives a promising solution to speed up the plastic decomposition process by a significant amount.

Most plastics take around 20 to 500 years to decompose, depending on the type and size. Plastics dumped in landfills take even longer to decompose (up to 1,00 years) since they are not exposed to air and sunlight, which accelerates the process. Even as the plastics slowly degrade, they can leach toxic chemicals and microplastics into our soil, air, and water. When mushrooms decompose these plastics, they also break down any hazardous substances, making them a safe and sustainable method for our plastic problem.

Using oyster mushrooms to break down butts

While certain fungi have the ability to feed off plastic waste, it’s worth noting that not all plastic-consuming fungi can break down every kind of plastic. There are several varieties of plastics, and these fungi tend to have preferences over which ones they’ll successfully decompose. Still, researchers have identified oyster mushrooms as a particularly effective species for consuming and decomposing cellulose acetate, the plastic material that’s commonly used in cigarette filters.

In one study, a researcher from the University of Maine tested three types of oyster mushrooms on different kinds of cigarette substrates. The results of the study found that P. djamor (pink oyster mushrooms) accelerated biodegradation the fastest and produced the highest quality of mushrooms (1). The safety of mushrooms grown on plastics has yet to be tested, but most of the toxic components are digested entirely by the mushrooms, except for heavy metals like copper, zinc, and lead. With further research, this method could be used as a food source, especially in countries with limited food sources and high pollution.

Oyster mushrooms feed on a variety of different substrates — from wood to straw, corncobs, and coffee grounds, and yes, also several types of plastics. According to Amanda Morgan, the chief executive and head of research at Fungi Solutions, “Mushrooms have an incredibly adaptive digestive system.” She also notes that “This particular material is quite toxic so it takes a while to encourage them in that direction, but we now have a strain of fungi that is going just exclusively on cigarette butts alone.” While these mushrooms have adapted to a cigarette substrate, it can take some time for them to fully consume all of the toxic materials. Regardless, this strain of fungi has the potential for further research and development.

Turning plastics into sustainable goods

Mushrooms digest their food and break down matter through their mycelium, which is an interconnected structure made of thread-like filaments called hyphae. Mycelium produces enzymes that can break down matter and make it digestible for the entire fungal organism. Since mycelium grows quickly and is made from natural polymers like chitin and cellulose, it makes the perfect sustainable material for several products. Fungi Solutions is killing two birds with one stone with their program. Their mushrooms will reduce cigarette waste while also turning the mycelial byproduct into a polystyrene replacement that can be used for things like packaging and insulation. The mycelium products are sustainable and entirely biodegradable once the cigarette plastics are entirely broken down. However, while the oyster mushroom strain has shown great promise in decomposing plastic materials, further research must be done to determine how to remove the remaining heavy metals that cigarette butts can leave behind.

The CigCycle program will continue its research on the oyster mushroom method to ensure it can effectively reduce harmful compounds before solidifying it into a legitimate product. Until then, Fungi Solutions will hold off on any product production until the process is perfected. “We still need to be doing a fair bit of lab testing to have a look at the toxicity breakdown before and after remediation, but we are hoping that we can develop a nice clean material byproduct from this process,” says Morgan. Nonetheless, science is getting one step closer to finding a natural solution to our plastic problem. Even without a viable product, we now know that mushrooms are capable of decomposing cigarette waste which is a major win for reducing plastics in our environment and landfills. 

References

1. Updyke, Raymond. 2014. “Biodegradation and Feasibility of Three Pleurotus Species on Cigarette Filters.” Digitalcommons.library.umaine.edu. https://digitalcommons.library.umaine.edu/honors/192/.