SCIENCE NEWS | Researchers in the United States have devised a building material that can multiply itself. The stuff is based on bacteria that form the hard calcium carbonate and glue sand grains together.
Concrete made from bacteria.
A team of researchers from the University of Colorado Boulder first built a solid structure from a mixture of hydrogel and sand. This hydrogel retains moisture and nutrients, two things that the bacteria need to thrive.
The micro-organisms (cyanobacteria) went to work in this bacteria-friendly environment. They convert the nutrients into calcium carbonate, a process that is similar to the formation of shells in the ocean. Calcium carbonate is a hard material that gives a structure its strength. In this case this hard substance forms the connection between the sand grains.
LIVING MATERIAL By putting a mixture of sand, hydrogel and bacteria in molds, 'stones' were created from a new, living material (see the photo below). This exotic material can be an answer to the enormous worldwide use of concrete. Although that is a fantastic building material - strong, versatile, it will last a long time - but making cement (the powder with which you prepare concrete) is accompanied by a considerable emission of the greenhouse gas CO 2 (also read the large article ' Clean concrete ' that we had about this in 2016). Building with concrete is responsible for around 6 percent of global CO2 emissions.
