The U.S. Department of Energy is funding a biotechnology team to explore using enzymes to "digest" waste polyester textiles into the chemical feedstocks needed to produce new polyester. According to WWD, the effort is led by Protein Evolution, a company headquartered in New Haven, Connecticut, with the goal of verifying whether this biological process can work at industrial scale and drive costs down to a level competitive with conventional polyester feedstocks.

According to information disclosed by WWD, partners include Xytel, which specializes in pilot plants, and the research institution formerly known as the U.S. National Renewable Energy Laboratory, now renamed "Rocky Mountain National Laboratory." The DOE Office of Critical Minerals and Energy Innovation is funding 56 projects totaling $117 million in this round, and Protein Evolution's research is expected to receive $3 million, though the final figure may still be adjusted during negotiations.

The DOE says the goal is clear: to create a recycling method whose cost can compete with virgin polyester feedstocks.

From an industry-wide perspective, the scale of polyester is enormous. Citing data from Textile Exchange, WWD reports that polyester accounted for 59% of global fiber production in 2024, with 88% of that still coming from virgin resources; most recycled polyester on the market is made from plastic bottles, and the share truly derived from waste textiles is less than 1%. This is one reason the DOE is willing to place its bet.

On the technical path, enzymes can break down PET plastic at the molecular level into terephthalic acid and ethylene glycol, which after purification can re-enter conventional polyester production lines. WWD notes that, unlike the low-quality material produced by repeated mechanical recycling, this route promises feedstock close to virgin polyester in quality.

But the difficulties are also concentrated. Used textiles have complex compositions and are often dyed and chemically finished; polyester fibers themselves are highly crystalline, making them hard for enzymes to "bite" into. If the material must first be softened by heating or extra processing steps, much of the energy and cost savings would be eaten away.

A 2022 study by Rocky Mountain National Laboratory showed that the team screened more than 250 million protein sequences before finding an enzyme that could act on crystalline PET. In bioreactor tests, nearly 98% of PET was converted into terephthalic acid and ethylene glycol after 48 hours. The study also estimated that, by avoiding some energy-intensive steps, supply chain energy consumption could be reduced by 45% and greenhouse gas emissions by 38% compared with enzymatic hydrolysis schemes that first soften the material; the cost of recovering terephthalic acid from waste clothing and carpets could be below about $0.45 per pound—meaning savings for manufacturers and ultimately for consumers. However, these results are not specific to Protein Evolution's process, and the DOE has not yet published cost or technical performance targets for the newly funded project.

Protein Evolution's award follows years of buildup: the company previously operated privately, emerged publicly in 2022 with more than $20 million in initial funding, and its enzyme design platform combines artificial intelligence and synthetic biology. Its first product, Biopure, is used to break down plastic and textile waste into feedstocks for new materials. At COP28 in 2023, designer Stella McCartney showed a parka using recycled polyester supplied by the company, though that sample relied on rigid packaging and industrial polyester scraps rather than old clothes. In November 2024, Protein Evolution announced a partnership with Slovenian biotechnology company Acies Bio to expand enzyme production and plans to build a Biopure demonstration facility in 2025.

For the textile recycling industry, the significance of this funding is that difficult-to-process blended and dyed polyester waste is being connected to a "molecular-level" circular recycling chain; once costs can match virgin polyester, "old clothes into new fabric" will no longer be just a niche supplement to physical recycling. But how far it is from industrial validation and commercialization still has no public data to answer.

Source: DOE puts $3 million behind polyester-eating enzymes to turn textile waste into new polyester · Originally published 2026-09-08