photo by: Contributed

Five color variants of the fungus Aspergillus nidulans. The dark green color strain is the wild-type and the others are pigment production pathway mutants or deletants.

When aircraft parts, wind turbines, sports equipment and other things made from carbon fiber materials reach the end of their lifespans, we’ll have hundreds of thousands of tons of waste to clean up — waste that’s proved tough to recycle in the past.

But a team including University of Kansas researchers has developed a process to break some of these complex substances down, and it involves a fuzzy fungal friend that ensures even the byproducts won’t go to waste.

The difficulty in recycling composite material made of carbon fibers comes from how the material is made. Berl Oakley, a distinguished professor of molecular biology at KU, said in a KU news release that the composite is “usually a woven material combined with a matrix, often made of epoxy or polystyrene, that holds it together.” But the materials can’t just all be melted down together and then re-formed. Instead, if you want to recycle them, you have to separate them out.

“You have a mixture of the fabric and the matrix, so the goal is to recover the fabric for reuse and also dissolve the matrix without creating something toxic or wasteful,” Oakley said in the release.

photo by: University of Kansas

Berl Oakley

Now, the release said, a partnership between KU and University of Southern California researchers has developed a chemical procedure for doing just that. Before, according to a statement from USC, the only recycling method available involved burning off the matrix. But the team’s method breaks down and removes the matrix from the carbon fibers so that not only can the fibers can be repurposed, but you can also make something useful out of the matrix byproducts.

photo by: Contributed

Five color variants of the fungus Aspergillus nidulans. The dark green color strain is the wild-type and the others are pigment production pathway mutants or deletants.

That last part is where the hungry fungus comes in. It’s called Aspergillus nidulans, and it can feed on a matrix byproduct known as benzoic acid – a white, crystalline powder that’s sometimes used as a preservative in foods or to mimic snow in snow globes.

“We knew that a fungus that we work with, Aspergillus nidulans, could use benzoic acid as a carbon source (to help it grow),” Oakley told the Journal-World. “Aspergillus is really good at growing on all kinds of things that you might not think would be hospitable.”

The goal is to use the fungus to turn that benzoic acid into a valuable chemical compound called octatrienoic acid, or OTA. Oakley said that researchers had used bacteria to produce OTA before, but his team was able to engineer a strain of the fungus that could produce much larger amounts.

“We are making a lot higher amounts, about 20 times as much as the bacteria is able to do,” Oakley said. “And we suspect that we can go higher and can do better than we’ve done so far by making some additional strain changes to the fungus that we’re using.”

The OTA can then be used in medical applications for things like antibiotics or anti-inflammatory drugs, said Clay Wang of USC, a longtime collaborator with Oakley, in USC’s statement. Wang said the discovery is important because it shows a new, more efficient way to turn what was previously considered waste material into something valuable that could be used in medicine.

According to Science Daily, projections suggest that materials such as carbon fiber fabric and polymer composites will result in significant waste in the future. By 2030, an estimated 6,000 to 8,000 aircraft containing these materials will reach the end of their lifespan, and by 2050, retired wind turbines will contribute 483,000 tons of composite waste.

photo by: Adobe Stock

Carbon fiber composite material.

Oakley said that the KU team will be working to make the fungus even more efficient, and that the needs for scalability and profitability will be kept in mind if the new carbon-fiber recycling method is to be applied at an industrial scale.

“I hope we’re able to make useful products in a way rather than just dumping things into landfills,” Oakley said.