Team:Newcastle

Project description

Microcracks in concrete undermine structural integrity and are inaccessible to conventional repair methods. Bacteria of the Bacillus genus could be the ideal candidates for concrete repair since they are able to precipitate CaCO₃ (Use of bacteria to repair cracks in concrete, Tittelboom et al, cement and concrete research (2009)).

Our project aims to fill cracks in concrete with a mixture of:

• CaCO₃ , which has the same expansion coefficient as concrete.
• Glue, which is required to gel together the CaCO₃ crystals.
• Filamentous Bacillus subtilis cells, which will act as reinforcements like the steel fibres found in concrete.

To protect the environment our project will also include a design for a kill switch. To enable Bacillus subtilis 168 to swim down the microcracks, we will introduce the required swarming genes from strain 3610. To coordinate the bacteria and trigger calcium carbonate precipitation and filament formation once they have reached a sufficient density inside a microcrack we will develop a subtilin-based cell-signalling system, building on the subtilin sensing system previously designed by Newcastle 2008’s iGEM team.