The leftover yeast from brewing beer, wine or even to make some pharmaceuticals can be repurposed to produce high-performance fibres stronger than natural fibres with significantly less environmental impact.
The yeast biomass — composed of proteins, fatty molecules called lipids and sugars — left over from alcohol and pharmaceutical production is regarded as waste, but lead author Melik Demirel, Pearce professor of Engineering and Huck Chair in Biomimetic Materials at Penn State, said his team realised they could repurpose the material to make fibres using a previously developed process. The researchers successfully achieved pilot-scale production of the fibre — producing more than 1,000 pounds — in a factory in Germany, with continuous and batch production for more than 100 hours per run of fibre spinning.
Penn State researchers have developed high-performance, eco-friendly fibres from leftover yeast biomass from brewing and pharmaceuticals.
The fibres are cheaper, stronger, biodegradable, and require far less land and water than cotton or wool.
Scalable production could reduce fashion’s environmental impact while freeing farmland for food crops, according to lead researcher Melik Demirel.
They also used data collected during this production for a lifecycle assessment, which assessed the needs and impact of the product from obtaining the raw fermentation byproduct through its life to disposal and its cost, and to evaluate the economic viability of the technology. The analysis predicted the cost, water use, production output, greenhouse gas emissions and more at every stage. Ultimately, the researchers found that the commercial-scale production of the fermentation-based fibre could compete with wool and other fibres at scale but with considerably fewer resources, including far less land — even when accounting for the land needed to grow the crops used in the fermentation processes that eventually produce the yeast biomass.
“Just as hunter-gatherers domesticated sheep for wool 11,000 years ago, we’re domesticating yeast for a fibre that could shift the agricultural lens to focus far more resources to food crops,” said Demirel, who is also affiliated with the Materials Research Institute and the Institute of Energy and the Environment, both at Penn State.
“We successfully demonstrated that this material can be made cheaply — for $6 or less per kilogram, which is about 2.2 pounds, compared to wool’s $10 to $12 per kilogramme — with significantly less water and land but improved performance compared to any other natural or processed fibres, while also nearly eliminating greenhouse gas emissions. The saved resources could be applied elsewhere, like repurposing land to grow food crops.”
Demirel’s team has spent over a decade developing a process to produce a fibre from proteins. Inspired by nature, the fibre is durable and free of the chemicals other fibres can leave in the environment for years, the study said.
“We can pull the proteins as an aggregate — mimicking naturally occurring protein accumulations called amyloids — from the yeast, dissolve the resulting pulp in a solution, and push that through a device called a spinneret that uses tiny spigots to make continuous fibres,” Demirel said, explaining the fibres are then washed, dried and spun into yarn that can then be woven into fabric for clothes. He also noted that the fibres are biodegradable, meaning they would breakdown after disposal, unlike the millions of tons of polyester clothing discarded every year that pollutes the planet. “The key is the solution used to dissolve the pulp. This solvent is the same one used to produce Lyocell, the fibre derived from cellulose, or wood pulp. We can recover 99.6 per cent of the solvent used to reuse it in future production cycles.”
The idea of using proteins to make fibre is not new, according to Demirel, who pointed to Lanital as an example. The material was developed in the 1930s from milk protein, but it fell out of fashion due to low strength with the advent of polyester.
“The issue has always been performance and cost,” Demirel said, noting the mid-20th century also saw the invention of fibres made from peanut proteins and from corn proteins before cheap and stronger polyester ultimately reigned.
Beyond producing a quality fibre, Demirel said, the study also indicated the fibre’s potential on a commercial scale. The models rolled their pilot-scale findings into simulated scenarios of commercial production. For comparison, about 55 million pounds of cotton are produced globally every year and just 2.2 pounds — about what it takes to make one T-shirt and one pair of jeans — requires up to 2,642 gallons of water. Raw cotton is relatively cheap, Demirel said, but the environmental cost is staggering.
“Cotton crops also use about 88 million acres, of farmable land around the world — just under 40 per cent of that is in India, which ranks as ‘serious’ on the Global Hunger Index,” Demirel said. “Imagine if instead of growing cotton, that land, water, resources and energy could be used to produce crops that could feed people. It’s not quite as simple as that, but this analysis demonstrated that biomanufactured fibres require significantly less land, water and other resources to produce, so it’s feasible to picture how shifting from crop-based fibres could free up a significant amount of land for food production.”
In 2024, 733 million people — about one in 12 — around the world faced food insecurity, a continued trend that has led the United Nations to declare a goal of ‘Zero Hunger’ to eliminate this issue by 2030. One potential solution may be to free land currently used to grow fibre crops to produce more food crops, according to Demirel. Current production methods not only use significant resources, he said, but more than 66 per cent of clothing produced annually in the US alone ends up in landfills. Demirel’s approach offers a solution for both problems, he said.
“By leveraging biomanufacturing, we can produce sustainable, high-performance fibres that do not compete with food crops for land, water or nutrients,” Demirel said. “Adopting biomanufacturing-based protein fibres would mark a significant advancement towards a future where fibre needs are fulfilled without compromising the planet’s capacity to nourish its growing population. We can make significant strides towards achieving the ‘Zero Hunger’ goal, ensuring everyone can access nutritious food while promoting sustainable development goals.”
Demirel said the team plans to further investigate the viability of fermentation-based fibres at a commercial scale.
Fibre2Fashion News Desk (RR)