Researchers from the University of Vienna, Imperial College London and RMIT University in Australia created a leather made of fungi that could be the best option for leather-based on its sustainability and cost compared to animal or plastic-based leathers.

Leather made from fungi uses fewer hazardous chemicals and releases less extra carbon into the atmosphere to create a leather that is on par with traditional, animal-based leather with the same durability and flexibility.

A handbag made from fungal leather, courtesy of Bolt Threads (USA). Source: RMIT

Traditional leather has ethical and environmental issues in its production. Raising livestock has negative effects on the environment, including deforestation, and producing leather uses harmful chemicals that can leak into the groundwater. Plastic-based leather alternatives, while vegan, are made with polymers polyurethane (PU) or polyvinylchloride (PVC), which are made from fossil fuels and are not biodegradable. Fungi-based leathers overcome all of these issues.

Fungi leather is created by upcycling low cost agricultural and forestry by-products, like sawdust. These products are used as feedstock to grow mycelium. After a few weeks, the fungal sheet is harvested, physically and chemically treated by pressing and crosslinking. This process produces a material with a similar feel to animal leather. It is mostly made up of biodegradable chitin and glucan biopolymers.

The team says that one challenge in the fungi leather’s production is that it can be difficult to make consistent and good quality mycelium sheets with uniform growth and consistent thickness, color and mechanical properties.

A paper on this new material was published in Nature Sustainability.