Microbial upcycling of plastic: from scenario evaluation to the wet lab

Over 365 million tons of plastics were produced worldwide in 2020, with significant growth expected in the near future, resulting in the global challenge of end-of-life management. Landfill is still the major end-of-life treatment, with the danger of environmental pollution, while true recycling is difficult for most plastic fractions. The reasons are manifold, including mixed plastic, additives, and polymer deterioration during the recycling. Also the low price of virgin plastic makes the use of recycled raisin less attractive. Hence, new ideas that give room for new incentives are required for the recycling of plastics. The recent identification of enzymes that degrade plastics previously considered to be non-biodegradable opens up opportunities to steer the plastic recycling industry into the realm of biotechnology.
We here elucidate in detail the upcycling of plastic waste by feeding plastic monomers as carbon source to microbial plastic producers.¹ The degradation of plastic and the possibilities to produce valuable products from the resulting monomers will be evaluated.² Novel value chains include products derived from de novo lipid synthesis like secreted OH-fatty acid derivatives.³ The envisaged contributions to improve sustainability of the plastic industry will be discussed.

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