Startup raises $65 million to "grow" cement

• Other investors include Celesta Capital, Novo Holdings and Martin Marietta Materials.

How it works, per FastCompany's Adele Peters: "The company starts with recycled aggregate, the tiny bits of material that cement holds together in concrete. Then it adds its (safe) strain of bacteria, along with calcium, carbon, and nutrients. The combination jump-starts the creation of calcium carbonate, the “biocement” that acts like glue. Unlike traditional cement manufacturing, it works in ambient temperatures, without the need for high heat."