Engineers have developed a building material that uses the root-like mycelium of a fungus and bacteria cells. Their results, publishing April 16 in the Cell Press journal Cell Reports Physical Science, show that this material—which is manufactured with living cells at low temperatures—is capable of self-repairing and could eventually offer a sustainable alternative for high-emission building materials like concrete.
"Biomineralized materials do not have high enough strength to replace concrete in all applications, but we and others are working to improve their properties so they can see greater usage," said corresponding author Chelsea Heveran, an assistant professor at Montana State University.
Compared to other similar biomaterials, which typically are only usable for a few days or weeks, Heveran's team's materials—which are made using fungal mycelium and bacteria—are useful for at least a month.
"This is exciting, because we would like for the cells to be able to perform other functions," says Heveran.
When the bacteria live within the material longer, their cells are able to perform several useful functions, including self-repairing when damaged and cleaning up contamination.
Materials made from once-living organisms are beginning to enter the commercial market, but those made with organisms that are still alive have proven challenging to perfect—both because of their short viability periods and because they tend to lack the complex internal structures needed for many construction projects.
To address these challenges, the team, led by first author Ethan Viles of Montana State University, explored using fungal mycelium as a scaffold for biomineralized materials, inspired by the fact that mycelium had previously been used as a scaffold for packaging and insulation materials. The researchers worked with the fungus species Neurospora crassa and found that it could be used to craft materials with a variety of complex architectures.
"We learned that fungal scaffolds are quite useful for controlling the internal architecture of the material," said Heveran. "We created internal geometries that looked like cortical bone, but moving forward, we could potentially construct other geometries too."
The researchers hope their new biomaterials can help replace building materials with high carbon footprints like cement, which contributes up to 8% of all carbon dioxide emissions produced from human activities. As a next step, they plan to further optimize the materials by coaxing the cells to live even longer and figuring out how to manufacture them efficiently on a larger scale.
