homehome Home chatchat Notifications


Bacteria turns plastic waste into super-strong spider silk

Researchers found that the bacteria not only consume the plastic but also transform it into something extraordinary.

Tibi Puiu
January 25, 2024 @ 9:08 pm

share Share

Bacteria turns plastic waste into spider silk
Credit: DALL-E 3.

Scientists have engineered bacteria capable of converting plastic waste into a versatile and eco-friendly form of spider silk. On the one hand, scaling this method up could address the growing global challenge of plastic pollution. On the other hand, it also provides an extremely valuable material.

Gram for gram, certain types of spider silk are five times stronger than steel. And, spider silk isn’t just strong; it’s incredibly flexible. It can stretch up to five times its original length without breaking.

Plastic waste to silk

Polyethylene plastic, commonly used in single-use items, has long been a bane for the environment. It can persist for centuries before it degrades — and even this timeline is uncertain. Researchers at Rensselaer Polytechnic Institute looked for a solution in the form of Pseudomonas aeruginosa, a bacterium with a natural appetite for this kind of plastic. To their surprise, they found that these bacteria not only consume plastic but also transform it into something extraordinary.

The process begins with the depolymerization of polyethylene, breaking it down into a form the bacteria can consume. This is similar to how humans have to cut and chew their food so it can be digested inside the gut. Once “fed” with this plastic-derived wax, the bacteria ferment it, akin to how yeast transforms sugars in bread-making. After 72 hours of fermentation, the resulting silk protein, reminiscent of cotton balls, can be further processed into usable forms.

Silk proteins generated by bacteria engineered to convert polyethylene into this multipurpose material. Credit: Rensselaer Polytechnic Institute
Silk proteins generated by bacteria engineered to convert polyethylene into this multipurpose material. Credit: Rensselaer Polytechnic Institute.

“Spider silk is nature’s Kevlar,” said Helen Zha, an assistant professor of chemical and biological engineering and one of the scientists leading the project. “It can be nearly as strong as steel under tension. However, it’s six times less dense than steel, so it’s very lightweight. As a bioplastic, it’s stretchy, tough, nontoxic, and biodegradable.”

“It’s a low-energy, non-toxic method,” Zha adds. “Nature’s best chemists couldn’t achieve this transformation, but these bacteria can.”

While this breakthrough is promising, scaling production up for commercial purposes remains a challenge. “Our next steps involve optimizing the process,” says Professor Mattheos Koffas. The team’s ambition is to refine this bacterial alchemy, turning a vision of sustainable material production into a reality in the commercial market.

“This study establishes that we can use these bacteria to convert plastic to spider silk. Our future work will investigate whether tweaking the bacteria or other aspects of the process will allow us to scale up production,” Koffas said.

The findings appeared in the journal Microbial Cell Factories.

share Share

AI 'Reanimated' a Murder Victim Back to Life to Speak in Court (And Raises Ethical Quandaries)

AI avatars of dead people are teaching courses and testifying in court. Even with the best of intentions, the emerging practice of AI ‘reanimations’ is an ethical quagmire.

This Rare Viking Burial of a Woman and Her Dog Shows That Grief and Love Haven’t Changed in a Thousand Years

The power of loyalty, in this life and the next.

This EV Battery Charges in 18 Seconds and It’s Already Street Legal

RML’s VarEVolt battery is blazing a trail for ultra-fast EV charging and hypercar performance.

DARPA Just Beamed Power Over 5 Miles Using Lasers and Used It To Make Popcorn

A record-breaking laser beam could redefine how we send power to the world's hardest places.

Why Do Some Birds Sing More at Dawn? It's More About Social Behavior Than The Environment

Study suggests birdsong patterns are driven more by social needs than acoustics.

Nonproducing Oil Wells May Be Emitting 7 Times More Methane Than We Thought

A study measured methane flow from more than 450 nonproducing wells across Canada, but thousands more remain unevaluated.

CAR T Breakthrough Therapy Doubles Survival Time for Deadly Stomach Cancer

Scientists finally figured out a way to take CAR-T cell therapy beyond blood.

The Sun Will Annihilate Earth in 5 Billion Years But Life Could Move to Jupiter's Icy Moon Europa

When the Sun turns into a Red Giant, Europa could be life's final hope in the solar system.

Ancient Roman ‘Fast Food’ Joint Served Fried Wild Songbirds to the Masses

Archaeologists uncover thrush bones in a Roman taberna, challenging elite-only food myths

A Man Lost His Voice to ALS. A Brain Implant Helped Him Sing Again

It's a stunning breakthrough for neuroprosthetics