Glue made from genetically modified bacteria can knit cracks in concrete
The genetically-modified microbe has been programmed to swim down fine cracks in the concrete. Once at the bottom it produces a mixture of calcium carbonate and a bacterial glue which combine to ‘knit’ the building back together.
The ‘BacillaFilla’ eventually hardens to become the same strength as the surrounding concrete and is designed to make buildings last longer.
Filler: The bacteria could be injected into a crack in a concrete wall and would self-germinate until it had filled the gap.
Joint project instructor Dr Jennifer Hallinan said: ‘Around five per cent of all man-made carbon dioxide emissions are from the production of concrete, making it a significant contributor to global warming.
‘Finding a way of prolonging the lifespan of existing structures means we could reduce this environmental impact and work towards a more sustainable solution.
’This could be particularly useful in earthquake zones where hundreds of buildings have to be flattened because there is currently no easy way of repairing the cracks and making them structurally sound.”
The bacterium used by researchers is called Bacillus subtilis and is commonly found in soil.
The BacillaFilla spores only start germinating when they make contact with concrete – triggered by the very specific pH of the material – and they have an in-built self-destruct gene which means they would be unable to survive in the environment.
Once the cells have germinated, they swarm down the fine cracks in the concrete and are able to sense when they reach the bottom because of the clumping of the bacteria.
This clumping activates concrete repair, with the cells differentiating into three types: cells which produce calcium carbonate crystals, cells which act as reinforcing fibres and cells which produce a glue which acts as a binding agent and fills the gap.
The microbial glue was designed by students at Newcastle University as part of a major international science competition in the US.
Article from: dailymail.co.uk