Complete of the article that helps toughen the new concrete, notes wil Srubar. He is a scientist at the University of
Colorado Boulder. He's also part of the team that developed the concrete.
His team mixed the microbes together with sand. They also added a protein found in bones called
gelatin. Then, they added nutrients that help the bacteria grow. The scientists chose to add
cyanobacteria to their concrete. Cyanobacteria are like the bacteria or green algae that grow in a
fish tank. These bacteria can perform photosynthesis. It is a process that uses carbon dioxide and
light to make food.
The process does not release carbon dioxide, unlike cement. It even stores carbon in the living
cement
The bacteria also make a mineral called calcium carbonate. It is an important ingredient in
cement. Those bits make the new concrete tougher once it is cooled. Cooling the mixture also
makes the gelatin harden. It's just like cooling a jiggly gelatin dessert.
Imagine Living LEGOs, But With Flaws
What if the bacteria survived in the hardening concrete? Srubar's team thought the bacteria might
help make material for new bricks, too. To test the idea, they split a block and melted its pieces.
They added more nutrients to the mix. The bacteria grew. Then, they added sand. They had
enough bacteria and material to build two new concrete blocks. The team split and grew the
material until they made eight bricks from the original block.
But this new approach won't put an end to regular
concrete just yet. Srubar's group works in a lab where
contamination is easy to avoid. In the real world,
other microbes might get into the mix. Other
microbes could take over if they grow faster than the
cyanobacteria. Those other microbes might prove
harmful. Or they might change how the concrete
behaves
Cyanobacteria also need certain things to stay alive.
They won't survive well where it's dry. The living
concrete may only work in places that are warm and humid all year.
Scientists are excited even if it takes a while. There are lots of ways living materials might be used
in the world. "Nature has figured out a lot of really cool things that we can use in our day-to-day
lives," Srubar says. "We just have to pay a little more attention."