BY SHARNA SAHA
Concrete is everywhere—our roads, bridges, buildings, and even sewage systems depend on it. But do we ever stop to consider its true impact? The construction industry uses 30 billion metric tons of concrete annually—equivalent to six Pyramids of Giza—yet its production is one of the largest contributors to global carbon emissions. Cement, a key ingredient in concrete, is made by firing limestone, clay, and other materials in a kiln, a process that emits nearly one pound of CO₂ for every pound of concrete produced. In 2022, concrete was responsible for 8% of the world’s total CO₂ emissions, making it a pressing environmental concern¹˒². Fortunately, a groundbreaking innovation could help change this.
In the Netherlands, a centuries-old estate is undergoing renovations using self-healing concrete—an advanced material embedded with living bacteria that can repair cracks before they become structural threats³. While concrete is strong, it is still prone to cracking, especially when water seeps in and corrodes the steel reinforcement inside. This deterioration weakens structures, sometimes leading to collapse. Governments and private companies spend billions annually on repairs, and when buildings become unsalvageable, the demolition generates tons of waste while fueling demand for even more concrete².
Enter Green Basilisk, a Dutch biotech company with a brilliant solution: “seeding” concrete with bacterial spores and calcium lactate. These dormant spores remain inactive until water enters a crack, triggering Bacillus subtilis to digest the lactate and produce calcium carbonate (CaCO₃), sealing the gap within weeks and preventing further damage⁴˒⁵.
Green Basilisk offers products that can self-repair cracks in both new and existing structures while also consuming CO₂ emissions¹. Of course, businesses need to be profitable to continue innovating. Green Basilisk plans to sell regular concrete for $68–$91 per cubic meter, with an optional $46 per cubic meter surcharge for the self-healing feature. This might seem steep compared to traditional concrete at $44 per cubic meter, but when factoring in long-term maintenance and repair costs, the difference is negligible—some estimates suggest that repair costs for conventional concrete can reach 5–10% of total construction costs, while self-healing concrete lowers this to just 1%¹. And the company is already working on making it even cheaper by developing more affordable bacterial nutrients to replace calcium lactate. Some critics raise concerns about embedding bacteria in buildings, questioning potential health risks or material degradation, but studies show that the spores remain inert until activated and pose no harm to humans. Nutrient supplementation is minimal and designed to last for decades⁵.
But self-healing concrete is just the beginning. Other companies are exploring biological construction materials—from bacteria-grown bricks and tiles to fungi-based building materials. The University of Colorado, funded by the Defense Advanced Research Projects Agency (DARPA), is researching cyanobacteria that absorb CO₂ while forming living building bricks. By mixing bacteria with gelatin and sand, scientists trigger calcium carbonate precipitation, binding the material into solid blocks. The most fascinating part? These bricks can reproduce—one brick can generate up to eight new ones as bacterial colonies grow. The replication process typically occurs under controlled conditions over several days and is not active once the bricks are set in construction, ensuring structural integrity remains intact⁶.
Fungi are also emerging as game-changing biological builders. Some companies are using mushrooms and mycelium to create textiles, packaging, and even construction materials⁷. With over 85% of textiles ending up in landfills each year, pollution is a major concern. Microfibers from synthetic fabrics account for 30% of oceanic pollution, but replacing polyester with plant-based materials like seaweed, cactus fibers, and mycelium leather could significantly reduce environmental damage — some reports estimate up to a 90% reduction in carbon emissions compared to traditional synthetic materials². Mushroom-derived fabric offers a biodegradable alternative to synthetic leather, tackling both land and ocean pollution⁷.
The future of construction lies in biomaterials. By designing materials that function like living ecosystems, we can build a more sustainable world. Self-healing concrete is just the first step—as microbiologists and engineers push the boundaries of bio-architecture, the possibilities are endless.
Sharna Saha is a sophomore in Morse College.
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References
- van Genuchten, E. How CO₂ emissions can be reduced with self-healing concrete. Medium (2022). https://medium.com/climate-conscious/how-CO2-emissions-can-be-reduced-with-self-healing-concrete-d0ecab049545
- Jacoby, M. Alternative materials could shrink concrete’s giant carbon footprint. C&EN (2020). https://cen.acs.org/materials/inorganic-chemistry/Alternative-materials-shrink-concretes-giant/98/i45
- Stewart, A. The ‘living concrete’ that can heal itself. CNN Business (2018). https://www.cnn.com/2015/05/14/tech/bioconcrete-delft-jonkers/index.html
- Peplow, M. Bioconcrete presages new wave in environmentally friendly construction. Nat. Biotechnol. 38, 776–778 (2020). https://doi.org/10.1038/s41587-020-0595-z
- Castro-Alonso, M. J. et al. Microbially induced calcium carbonate precipitation (MICP) and its potential in bioconcrete: microbiological and molecular concepts. Front. Mater. 6, 126 (2019). https://doi.org/10.3389/fmats.2019.00126
- Bendix, A. Scientists created carbon-sucking ‘Frankenstein’ bricks using microbes. The material can spawn its own babies. Business Insider (2020). www.businessinsider.com/living-brick-material-bacteria-regenerates-2020-1
- Gomez, A. Mushroom fabric: Is clothing made from mushrooms & mycelium cells the future of fashion? The Uptide (2021). www.theuptide.com/mushroom-fabric-clothing-made-from-mushrooms-mycelium-cells/
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