Researchers have designed bacteria that can produce a special glue to knit together cracks in concrete structures. Technews Daily reports the genetically modified microbes have been engineered to swim down fine cracks in concrete and once at the bottom produce a mixture of calcium carbonate and a bacterial glue. The building is "knitted" back together as the glue combines with the filamentous bacterial cells and hardens to the same strength as the surrounding concrete. The bacterium tweaked by the researchers is called Bacillus subtilis and is commonly found in soil. Accordingly, the research team calls its building-healing agent "BacillaFilla." Its spores start germinating only when they make contact with concrete – triggered by the very specific pH of the material – and they have a built-in self-destruct gene that prevents them from proliferating away from the concrete target. Via MSNBC News. Thanks Jan van der Asdonk.