Some microorganisms secrete materials that can been used as a binder in e.g. self-healing concretes and bricks
Biomineralisation makes use of the ability of some microorganisms to secrete materials that react with the environment to form mineral particles. This has been most widely researched when it comes to urea-dependent biocementation, where the metabolic activity of a bacteria increases the carbonate concentration of their immediate surroundings. This causes the precipitation of calcium carbonate (CaCO3), which acts as a binder.
The first papers on biomineralisation were published in the 1970s, when the ability of bacteria to precipitate CaCO3 was demonstrated. The first application of the technology occurred about two decades later in the early 1990s, when it was utilised to protect the surface of monuments. Since then, biomineralisation has been applied to the remediation of cracks in concrete and the development of self-healing concrete, as well as for binding sand and aggregates into bricks.
Despite this development work, most biomineralisation technologies remain in an early-stage of development. They are also complex, resulting in high final costs, while their performance and durability are yet to be proven on an industrial scale. In the immediate future, it is likely that they will remain a niche technology.
However, the ability to create self-healing concretes is an important element of creating a more sustainable urban environment, reducing the need for maintenance and repair of concrete structures, as well as increasing their lifespan. To the extent that biomineralisation may contribute to this development, it will remain of interest to researchers.