By minimizing resource input and waste as well as emission and energy leakage circular economy concepts provide sustainable solutions to the increasing problem of resource limitations. In their recent publication (DOI: 10.1111/1751-7915.12734 ) in “Microbial Biotechnology” Austrian, Slovenian and UK scientists report on successful recycling of polyesters, one of the most used materials in the textile industry. They developed a strategy that breaks down poly(ethylene terephthalate) (PET) into its building blocks, i.e. terephtalic acid (TA) and ethylene glycol. These compounds arise from chemo-enzymatic PET hydrolysis. In the first step, PET undergoes high heat- and pressure-mediated conversion into TA and small oligomers. These oligomers are subsequently hydrolised by incubation with a fungal enzyme. Importantly, the PET depolymerisation procedure is water-based and does not involve toxic chemicals. It yields 97% pure TA, comparable with the commercial synthesis-grade. (Evidence derives from Fourier transform Raman analysis.)

The enzyme used, cutinase originating from a soft-rot fungus, was a gift from Novozymes. This company has established a large collection of enzymes which (from a biochemist´s point of view) hold considerable potential to turn diverse “waste” products into high-value-materials. See also https://report2016.novozymes.com/the-big-picture/in-a-nutshell

To close the cycle, subsequent studies should now focus on how PET can be synthesized from the recovered TA. Coordinated collection and processing of textile wastes among EcoInn´s partner countries appears a realistic vision, the fundament of which can be built in the Virtual Lab.