Fungal Scaffolds Create Living Building Materials That Stay Alive for Months
- Gauri Khanna
- 21 hours ago
- 3 min read
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Montana State University researchers developed biomineralised building materials using fungal mycelium scaffolds that maintain microbial viability for at least four weeks at elevated temperatures
The materials achieve structural strength through bacterial or fungal mineralisation whilst retaining living properties like potential self-healing capabilities
Mycelium scaffolds enable complex internal geometries inspired by bone structure, addressing limitations of previous engineered living materials
Concrete production accounts for 5-8% of global anthropogenic CO₂ emissions, yet demand for building materials continues rising. Researchers at Montana State University have demonstrated that fungal mycelium (the thread-like root structure of fungi) can serve as scaffolding for biomineralised building materials that remain alive far longer than previous attempts at engineered living materials.
Two Paths to Mineralisation
The research team, led by assistant professor Chelsea Heveran, worked with Neurospora crassa, a non-pathogenic fungus capable of producing urease enzymes. This enzyme catalyses urea breakdown, raising pH and enabling calcium carbonate precipitation; essentially creating mineral deposits that harden the material. The process mimics how marine organisms build coral reefs and shells.
The study explored two mineralisation approaches. In self-mineralisation, living N. crassa mycelium produced its own calcium carbonate crystals over 10 days. Alternatively, researchers killed the fungal scaffold through autoclaving, then inoculated it with Sporosarcina pasteurii, a ureolytic bacterium. This bacterial mineralisation proved more efficient, completing the process within 24 hours whilst producing stiffer mineral deposits.
Crucially, both approaches maintained high microbial viability. Living fungal scaffolds showed growth after four weeks of drying at 30°C, though some required physical disturbance to resume active metabolism. Bacterially mineralised scaffolds retained abundant viable bacteria, over 10,000 colony-forming units per millilitre, after the same period, even under elevated temperature conditions. By contrast, bacterial cultures without mycelium scaffolds lost viability entirely under identical drying conditions.
Structural Complexity Inspired by Bone
The Montana State team demonstrated unprecedented control over internal geometry by creating structures inspired by osteons: the concentric ring formations found in cortical bone. They grew N. crassa in planar sheets, wrapped these around plastic rods, then mineralised them with S. pasteurii. The resulting cylindrical structures were embedded in sand within beam-shaped moulds and mineralised again, creating composite materials with distinct architectural features visible through micro-CT scanning.
This geometric control represents a significant advance over previous biomineralised materials, which typically involved cementing sand or aggregate particles together without defined internal structure. Bone's osteonal architecture provides both mechanical toughness and channels for nutrient transport that are features potentially valuable for living building materials requiring cellular viability throughout their service life.
Viability Challenges Persist
The research revealed important limitations. Co-culturing living N. crassa with S. pasteurii proved unsuccessful, necessitating the autoclaving step for bacterial mineralisation. The reasons for this incompatibility remain undetermined. Additionally, whilst the team successfully created structurally complex specimens, mechanical property optimisation remains incomplete.
Previous attempts at engineered living materials using hydrogel scaffolds achieved viability lasting only days to weeks unless special storage conditions or anti-desiccants were provided. Hydrogels also degrade under outdoor humidity and temperature conditions. Mycelium's natural environmental durability (evolved for survival in soil and wood) appears to confer advantages for retaining moisture and supporting microbial survival.
Doctoral student Ethan Viles, the publication's first author, conducted the investigations demonstrating that mycelium scaffolds enable biomineralised materials to stay alive for extended periods. Heveran noted that because these materials retain viability longer, they might enable self-healing capabilities or act as environmental sensors: applications requiring living cells throughout a structure's service life.
Whether fungal-scaffolded biomineralised materials can achieve the decades-long viability required for practical building applications remains unproven. The four-week demonstration represents progress, yet structural materials serve for years or decades. Nevertheless, the work establishes mycelium scaffolds as viable platforms for manufacturing biomineralised materials with enhanced longevity and geometric complexity compared to earlier approaches.
