Highly Efficient 3D Templating of Microbially Induced Calcium Carbonate Precipitation

Microbially induced carbonate precipitation (MICP) of calcium carbonate (CaCO₃), the main ingredient of concrete or biocement, offers a carbon neutral or carbon negative route to create environmentally friendly and CO₂ capturing biocement. However, typical MICP process is slow and obtained CaCO₃ has different polymorphs. To enhance the growth of bacteria and its colonization and carbonation efficiency, while controlling the polymorphs of CaCO₃, we exploit the use of 3D printed minimal surfaces coated with biocompatible hydrogels as templates to immobilize non-pathogenic ureolytic bacteria genus S. pasteurii and photosynthetic cyanobacteria, respectively. We show that the amount of CaCO₃ crystals deposited on the 3D templates are an order of magnitude more than those deposited on a conventional agar gel in a petri dish. Inclusion of nanoporous materials that can capture CO₂ in bacteria growth medium further enhances bacteria growth and precipitation of CaCO₃.