A new fungus– and bacteria-based building material developed by Montana State University researchers demonstrates the ability to “heal” itself, an achievement that could pave the way toward self-repairing structures.
The new material promises major carbon reductions compared to more traditional materials such as concrete, which are commonly used in construction projects today. By mitigating some of the major drawbacks plaguing the current bio-based construction materials, the team hopes to move such materials closer to regular implementation.
Organic Construction
Bio-based construction materials already exist on the market, but developing a high-performing version incorporating live organisms has remained challenging. Keeping these organisms alive long enough to be functional has proven difficult, as has achieving the rigidity seen in conventional materials like concrete.
Led by Ethan Viles, the team looked beyond construction for inspiration, drawing from other applications of fungal mycelium, such as its use in packing and insulation. Their research identified Neurospora crassa, a type of bread mold, as well-suited for forming complex material structures. When paired with the bacteria Sporosarcina pasteurii, the resulting material could be mineralized into a strong, durable form suitable for construction.
“We like these organisms for several reasons,” co-author Chelsea Heveran told The Debrief. “First, they do not pose very much threat to human health. S. pasteurii is a common soil microorganism and has been used for years in biomineralization research, including in field-scale commercial applications. N. crassa is a model organism in fungal research.”
“We were excited that both of these microorganisms were ureolytic and could, therefore, potentially biomineralize the scaffolds,” Heveran added. “A good number of other bacteria and fungi could also potentially be used.”
Fungus for Building
The material is created by combining fungal mycelium and bacterial cells at low temperatures, resulting in much lower emissions than conventional materials like concrete. It also boasts a shelf life of at least a month—far exceeding that of many other biomaterials, which often last only days or weeks.
“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 materials that we are working with are made of lightweight constituents, like mineralized composites in nature,” Heveran told The Debrief. “One of the ways that nature strengthens lightweight composites is through exquisite microarchitecture. We hope to do more, using less, through engineering internal microarchitecture in more sophisticated geometries.”
Rising Interest in Bio-Materials
Interest in engineered living materials (ELMs) is growing as scientists and industry leaders explore the sustainability potential of structural products that can self-assemble, self-heal, or even perform photosynthesis.
“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 Heveran.
The material’s live bacterial cells enable self-repair and help manage contamination. Remarkably, the fungus remains alive even after hardening through crystallization. While the limits of its lifespan are still unknown, Heveran believes it could be substantial.
“[Use cases include] repairing small cracks before they become larger, could be very useful. Or, using microbes instead of extensive human labor could make repairing materials in remote or otherwise challenging locations,” adds Heveran.
Toward a More Sustainable Future
Cement production accounts for up to 8% of global human-made carbon dioxide emissions. Replacing it with bio-based alternatives like this new material could dramatically reduce the environmental footprint of building projects.
The Montana State team’s next steps include increasing the viability of the live cells in the material, in part by designing internal structures that promote microorganism longevity. They are also exploring the most efficient methods for scaling up production to commercial levels.
The paper, “Mycelium as a Scaffold for Biomineralized Engineered Living Materials,” appeared on April 16, 2025, in Cell Reports Physical Science.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.