According to Scientific American, cement is the most energy-intensive product on the planet. Global cement and concrete production accounts for 9% of all man-made carbon dioxide emissions annually. 

But it's hard to imagine a world without concrete when it’s the building block of nearly everything: homes, buildings, bridges, roads, and more. 

That’s why scientists at Montana State University Bozeman decided to think outside of the box when it came to creating a concrete alternative. 

“We asked ‘what if we could do it a different way using biology?’ That’s the vision,” Chelsea Heveran, an assistant professor of mechanical and industrial engineering, told CNN. 

Heveran is the senior author of a study published on April 16 in Cell Reports Physical Science, which explores the viability of using dense fungi and bacteria to create recyclable building materials. 

“We’re not the first ones to biomineralize something and call it a building material,” Heveran pointed out. 

Where their research team differs, Heveran explained, is the introduction of calcium carbonate (a chemical compound) to mycelium (the vegetative part of a fungus). 

Through a process called biomineralization, the calcium carbonate causes the mycelium to harden into bonelike structures called “scaffolds.” 

“If you want to keep [the bacteria] alive for longer so that you can do more with them, there’s been some challenges involved to extend that viability,” Heveran said. 

“So that’s why we gave them fungal mycelium scaffolds, because the mycelium is really robust, and in nature, sometimes it biomineralizes.”

Heveran said that biomineralized building materials are technically only “living” for a few days. But through their lab trials, Heveran and her team have been able to keep the microbes alive for at least four weeks. 

In the future, they hope to extend that time to months — or even years. 

“We’re really excited in our next work to ask the questions ‘could we seal a crack in the material?’ Or ‘could we sense something using these bacteria?’” Heveran posed. 

“Like, imagine you had poor air quality in your building, and these bricks were your walls. Could they light up to [indicate] that?” Heveran added. “Before, we couldn’t do any of that because the microbes weren’t alive enough, but they’re very alive now.”

Avinash Manjula-Basavanna, a senior research scientist at Northeastern University, weighed in on the Montana State University Bozeman experiments, adding that living building materials are still years away from replacing cement. 

“These kinds of experiments are done on a small scale,” Manjula-Basavanna said. “They are not necessarily a reflection of the bulk material properties. It’s not stiffness that people are interested in when it comes to construction materials. It is the strength, [the] load-bearing ability.”

“I think in the future, they could be useful for single-story buildings, these smaller structures — it’s very much feasible,” Manjula-Basavanna said. “It might be five to 10 years down the line.”

Even though she and her team are years away from using their fungi bricks in the “real world,” Heveran is willing to play the long game. 

The team has been working hard in the lab since 2020, when they first received a $500,00 grant from the National Science Foundation to kick off their research. 

Overall, Heveran is optimistic about the potential benefits of using living building materials. 

“There’s a lot of ‘ifs’ that would have to come into play for the average household to have a cost benefit from this,” Heveran said.

“But for society, it might be a lot cheaper when you’re trying to build infrastructure for a community that really needs it, or if you’re trying to build infrastructure in space, this might be a lot easier than carting cement and concrete up there,” she explained. 

“The possibilities are really exciting to me.”

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Header image via Bernard Spragg / Flickr