A team from Newcastle University in the UK and Vrije Universiteit Brussel in Belgium have grown fungus together with other ingredients to make a material they call myocrete, which can be used for lightweight construction. In another study, researchers from RMIT University in Australia engineered mycelium--the root-like network that is the foundation of fungal colonies--to create a sustainable fire-retardant material that could be used as building insulation or a leather substitute.

Mushrooms and other fungi usually grow in colonies. When mushrooms sprout up in the soil, they are just the tip of an iceberg. They are connected to a large network of white thread-like structures that grow under the soil or on rotting tree trunks, transporting nutrients to the fungus from the environment.

Researchers have tapped into mycelium to make leather substitutes, Styrofoam-like packaging materials, and even biodegradable substrates for electronic circuits.

With myocrete, the UK-Belgium team is trying to address the carbon footprint of the construction industry. Mycelium-based materials have excellent thermal and acoustic properties, which makes them promising for insulation and soundproofing. "They have potential to provide an inexpensive and sustainable class of materials suitable for the replacement of foams, timber and plastics for applications within building interiors," the researchers write.