Scientists around the world are discovering many environmental uses for fungi, and now Australian researchers are hoping oyster mushrooms will solve one of the world's biggest litter problems — what to do with the 4.5 trillion cigarette butts tossed away every year.
The key, according to fungi researcher Amanda Morgan, is convincing oyster mushrooms that cigarette butts are edible.
Fortunately, training a mushroom to digest a cigarette butt is "like training a baby to eat," Ms Morgan, founder and head of research and development at Fungi Solutions, says.
Once the mushroom begins the digestive process, it is able to break down the butts, including the microplastics in them, to create a reusable material, Ms Morgan says.
"It's a fascinating process to see, and most of our stuff is grown in glass so you can see the process," she said.
"Mushrooms put out fine webs of mycelium and the roots spread through the cigarette butt.
At the end of the process, the mushrooms will have eaten the microplastics in the cigarette butts' filters, leaving behind a material that can be used to create other products, such as boxes to collect cigarette butts.
Council collaboration 'a first'
Fungi Solutions, based in Melbourne, specialises in rescuing waste from landfill and using fungi to break down materials so they can be recycled or composted.
In an Australian-first collaboration with a council, Wollongong City Council in New South Wales will partner with Fungi Solutions researchers to collect cigarette butts and use the trained fungi to detoxify their plastic components.
“Council has invested in a number of new cigarette butt bins at key locations around our community," Wollongong City Council spokesperson Joanne Page said.
Trillions of butts littered every year
According to environmental organisation No More Butts, about 4.5 trillion cigarette butts are tossed away as litter worldwide every year.
The group says that in Australia, each year 8 billion butts are discarded into the environment — about a third of the total number of cigarettes consumed.
"It's the biggest issue we've got when it comes to litter," the group's spokesperson, Shannon Mead, said.
"It's the first time in Australia that we're working with a council to divert the butts we collect from landfill and it's fantastic to partner with Wollongong on this."
Making a meal of a cigarette
Oyster mushrooms send out long thin strands of white mycelium to explore their surroundings and gather nutrients — but eating a cigarette butt will be a new dining experience for them.
During the trial, the mushrooms will slowly recognise a food called cellulose acetate in the filter of the cigarette butt and begin to eat it.
That process also breaks down the plastics that are used to make the filters more durable.
"They [the mushrooms] are used to the cellulose, but we need to introduce the other elements, just like training a baby to eat," Ms Morgan said.
"From there you can take the culture and grow the next one."
Ms Morgan, who grew up in Wollongong, says her goal is to set up a remediation facility in her home city where butts can be transported to, treated, and turned into usable materials.
The trial is expected to take up to two years.
