Biocatalytic recycling of plastics: facts and fiction

Due to the lack of efficient end-of-life management, the mass production of plastics has resulted in serious environmental problems. Sustainable biological approaches using enzymes to degrade and recycle plastic waste are emerging as a complement to conventional methods to promote a circular economy of plastics. Only a fraction of the plastic waste generated is currently suitable for biocatalytic deconstruction and the development of economically and environmentally competitive processes is still pending. Inconsistent claims about new plastic-degrading enzymes reveal a need for robust and standardized analysis methods to ensure reproducible results and a realistic evaluation of their potential. This paper critically reviews enzymatic synthetic polymer degradation and its recycling challenges.