Imagine building parts of cars, airplanes and even buildings with bacteria that regenerate themselves, as well as living systems. A group of researchers at the University of Southern California in the United States believes it is possible.
Scientists are working with the bacteria called Sporosarcina pasteurii, known to secrete an enzyme called urease. When exposed to urea and calcium ions, urease produces calcium carbonate, found in bones and teeth.
“The materials we are making are alive and grow on their own. For centuries, we have been amazed at the sophisticated microstructures of natural materials, especially after microscopes were invented to look at these tiny structures,” says Professor Qiming Wang. “Now, we have taken an important step forward: we use live bacteria as a tool to directly develop incredible structures that cannot be made by ourselves.”
According to Wang, the main innovation of the research is that the bacteria are guided to cultivate calcium minerals to generate orderly structures similar to those of natural minerals.
For the studies, the group used a 3D lattice printing structure. The bacteria introduced into the structure cling to the crates and start to produce urease. The calcium carbonate crystals grow upwards, filling the empty spaces of the lattice. According to Wang, the material is extremely strong and can be used for aerospace panel and even vehicle infrastructures.
In addition, bacteria can also be used to repair parts if they are damaged. “An interesting view is that these living materials still have self-growing properties,” said Wang. “For example, if we use them on a bridge, we can use bacteria to grow the materials back and repair the damage when necessary,” he says.