RESUMEN
Significantly increased production of biobased polymers is a prerequisite to replace petroleum-based materials towards reaching a circular bioeconomy. However, many renewable building blocks from wood and other plant material are not directly amenable for polymerization, due to their inert backbones and/or lack of functional group compatibility with the desired polymerization type. Based on a retro-biosynthetic analysis of polyesters, a chemoenzymatic route from (-)-α-pinene towards a verbanone-based lactone, which is further used in ring-opening polymerization, is presented. Generated pinene-derived polyesters showed elevated degradation and glass transition temperatures, compared with poly(ϵ-decalactone), which lacks a ring structure in its backbone. Semirational enzyme engineering of the cyclohexanone monooxygenase from Acinetobacter calcoaceticus enabled the biosynthesis of the key lactone intermediate for the targeted polyester. As a proof of principle, one enzyme variant identified from screening in a microtiter plate was used in biocatalytic upscaling, which afforded the bicyclic lactone in 39 % conversion in shake flask scale reactions.
Asunto(s)
Monoterpenos Bicíclicos/química , Poliésteres/síntesis química , Animales , Catalasa/química , Bovinos , Escherichia coli/enzimología , Glucosa 1-Deshidrogenasa/química , Oxigenasas de Función Mixta/química , PolimerizacionRESUMEN
Several concurrent developments are shaping the future of plastics. A transition to a sustainable plastics system requires not only a shift to fossil-free feedstock and energy to produce the carbon-neutral building blocks for polymers used in plastics, but also a rational design of the polymers with both desired material properties for functionality and features facilitating their recyclability. Biotechnology has an important role in producing polymer building blocks from renewable feedstocks, and also shows potential for recycling of polymers. Here, we present strategies for improving the performance and recyclability of the polymers, for enhancing degradability to monomers, and for improving chemical recyclability by designing polymers with different chemical functionalities.