Could fungi one day replace plastics? Maybe, say researchers
14 March 2013
Fungi can be grown in almost any shape and be totally biodegradable. They may also have the potential to replace plastics: the secret is in the mycelia.
Fungi can be grown, under certain circumstances, in almost any shape and be totally biodegradable (photo: Union College)
Union College Biology Professor Steve Horton likens this mostly underground part of fungi to a tiny biological chain of tubular cells.
“It’s this linked chain of cells that’s able to communicate with the outside world, to sense what’s there in terms of food and light and moisture,” he said. “Mycelia can take in nutrients from available organic materials like wood and use them as food, and the fungus is able to grow as a result.”
“When you think of fungi and their mycelia, their function – ecologically – is really vital in degrading and breaking things down,” Horton added. “Without fungi, and bacteria, we’d be I don’t know how many meters deep in waste, both plant matter and animal tissue.”
Looking something like extremely delicate, white dental floss, mycelia grow in, through and around just about any organic substrate. Whether it’s leaves or mulch, mycelia digest these natural materials and can also bind everything together in a cohesive mat. And these mats can be grown in moulds, such as those that might make a packing carton.
Ecovative Design, in Green Island, New Yersey, is harnessing this particular mycological power and is being helped by Horton, and another Union researcher, Ronald Bucinell, associate professor of mechanical engineering.
Ecovative uses several species of fungi to manufacture environmentally-friendly products. The process starts with farming byproducts, like cotton gin waste; seed hulls from rice, buckwheat and oats; hemp or other plant materials. These are sterilized, mixed with nutrients and chilled. Then the mycelia spawn are added and are so good at proliferating that every cubic inch of material soon contains millions of tiny fungal fibres.
This compact matrix is then grown in a mould the shape of whatever item Ecovative is making. Once the desired texture, rigidity and other characteristics of the product are achieved, it’s extracted from its mould, heated and dried to kill the mycelia and thus stop its growth.
The all-natural products, the creation of which can take less than five days, have no allergy concerns and are completely non-toxic. More impressive is the fact that they’re also fire proof (up to a point), and just as water resistant as Styrofoam. They are also more UV-stable than foam since they are not petrochemical-based, and won’t emit volatile organic compounds. When exposed to the right microbes, they will break down in 180 days in any landfill.
Mycelium is comparatively inexpensive too as it can grow on farm waste that can’t be fed to animals or burned for fuel. Better yet, the fungi can be propagated without sunlight or much human oversight in simple trays at room temperature – no immense greenhouses with costly temperature-control systems needed. It also means a smaller carbon footprint and Ecovative is hoping to the point where they can displace all plastics and foams in the market.
And this is where Union professors and researchers, Steve Horton and Ronald Bucinell, are aiding them in this effort. In Horton’s lab, he and his students are tinkering with a species of fungus Ecovative uses in its manufacturing.
“We manipulate one strain in various ways to see if we can make versions of the fungus to suit certain applications the company has in mind,” Horton said. “For example, it might be helpful if Ecovative has certain versions that grow faster.”
Associate Professor of Mechanical Engineering Ronald Bucinell and his students also offer critical support to Ecovative’s research and development pipeline. Bucinell’s particular expertise is in experimental mechanics and the mechanics of reinforced materials and is tasked with seeing how strong sample material is under different parameters. This includes determining whether mycelia bind better to one plant material or another; and does the way it’s treated – with heat or via some other process – make it stronger or weaker.