Concrete Reinvented: How Biocement is Reshaping Construction

Biocement is an innovative and eco-friendly alternative to conventional cement, utilizing microbial activity to precipitate calcium carbonate (CaCO₃) for construction and soil stabilization purposes. It is primarily produced through a process known as microbial-induced calcium carbonate precipitation (MICP), most commonly facilitated by urease-producing bacteria such as Sporosarcina pasteurii. These bacteria enzymatically hydrolyze urea, increasing local alkalinity and generating carbonate ions that react with calcium ions to form cementitious CaCO₃. This process effectively binds soil particles or construction materials, enhancing structural durability while significantly reducing environmental impact.

Biocement typically comprises a mixture of urease-producing microorganisms, urea, and calcium salts. As the bacteria hydrolyse urea, they create an alkaline environment that promotes carbonate precipitation, leading to the formation of calcium carbonate. The production process is energy-efficient, often occurring under ambient conditions, and can involve various microbial agents, including bacteria, fungi, algae, and microbial consortia, broadening its applicability (Tegegn et al., 2024; Chu et al., 2011).

Among the studied organisms, Sporosarcina pasteurii remains the most extensively researched due to its high urease activity and efficiency in precipitating CaCO₃ (Tegegn et al., 2024; Tiwari et al., 2014). Other promising microbial strain,s such as Lysinibacillus sp. and Bacillus spp., have also demonstrated potential in biocementation applications (Ekprasert et al., 2022). Additionally, photosynthetic organisms like microalgae and cyanobacteria have been explored for their capacity to induce carbonate precipitation via urease enzymes and photosynthetic activity, further expanding the scope of biocementation (Ariyanti, 2012).

Biocement presents substantial environmental advantages over traditional Portland cement, notably by reducing CO₂ emissions, lowering energy consumption, and incorporating waste or low-cost materials in its production. As such, it represents a green technology that supports the sustainability goals of the construction sector by minimizing both carbon footprint and resource depletion (Porter et al., 2021).

This versatile material has been applied in a range of contexts, including soil strengthening, self-healing concrete, crack repair, and the stabilization of marine clays and coral gravels. Biocement treatment improves mechanical properties such as compressive strength and reduces permeability in various substrates. Beyond construction, research into calcium phosphate-based biocements is advancing their use in biomedical fields, particularly for bone repair (Veerappan et al., 2016).

References:

Chu, J., Ivanov, V., Stabnikov, V., He, J., Li, B., & Naemi, M. (2011). Biocement: Green Building- and Energy-Saving Material. Advanced Materials Research, 347–353, 4051–4054. https://doi.org/10.4028/www.scientific.net/amr.347-353.4051

Tegegn, Y. S. (2024). The Role of Microorganisms in Bio-cement Production: An Extended Review. Engineering and Applied Sciences, 9(6), 147-159. https://doi.org/10.11648/j.eas.20240906.13

Tiwari PKJoshi KRehman RBhardwaj VShamsudheen KV, Sivasubbu S, Scaria V 2014. Draft Genome Sequence of Urease-Producing Sporosarcina pasteurii with Potential Application in Biocement Production. Genome Announc 2:10.1128/genomea.01256-13.

https://doi.org/10.1128/genomea.01256-13

Ekprasert, J., Pongtharangkul, T., Chainakun, P., Fongkaew, I., Khanthasombat, K., Kamngam, R., Boonsuan, W., Ditta, Z. M., Seemakram, W., & Boonlue, S. (2022). Kinetic model of a newly-isolated Lysinibacillus sp. strain YL and elastic properties of its biogenic CaCO3 towards biocement application. Biotechnol. J., 17, e2100124. https://doi.org/10.1002/biot.202100124

Ariyanti, D., NoerAbyor, H., ayani, & Hadiyanto (2012). Feasibility of Using Microalgae for Biocement Production through Biocementation. Journal of bioprocessing & biotechniques, 2, 1-4.

Porter, H., Mukherjee, A., Tuladhar, R., & Dhami, N. K. (2021). Life Cycle Assessment of Biocement: An Emerging Sustainable Solution? Sustainability, 13(24), 13878. https://doi.org/10.3390/su132413878

Veerappan, K., & Chandru, P. (2016). A Brief Review on Biocement based Concrete.