Optimizing polymer biodegradation: the role of polyol-based biosolvents in laccase activity

Synthetic water-soluble polymers, such as poly(vinyl alcohol) (PVA), are widely used in various applications due to their ability to dissolve in water and their functional properties. However, their environmental impact is a growing concern, as PVA and similar polymers exhibit limited biodegradability under natural conditions, leading to persistence in aquatic environments and potential accumulation in ecosystems. Although certain microorganisms can degrade PVA, this process often requires specialized enzymes, such as pyrroloquinoline quinone (PQQ)-dependent dehydrogenases, which limits the efficiency and scalability of microbial degradation. Enzymatic degradation represents a promising and sustainable alternative for addressing the environmental persistence of aqueous soluble polymers. However, a high efficiency and applicability of such enzymatic processes remains a key challenge. This study explores the use of polyol-based biosolvents to improve the catalytic efficiency of laccase, an oxidoreductase enzyme. Laccase performance was evaluated in biosolvents with varying carbon chain lengths and hydroxyl group contents. Among the tested solvents, widely abundant glycerol notably increased enzyme efficiency. These findings highlight the promising role of biosolvents in optimizing laccase-driven polymer biodegradation, paving the way for more effective and sustainable approaches to polyolefin and plastic waste management. Ongoing research is focusing on refining these enzymatic systems to maximize degradation of PVA under eco-friendly conditions.

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020), financed by national funds through the FCT/MCTES (PIDDAC). This work is funded by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the project GREEN-PATH (Ref. 2023.15169.PEX, DOI 10.54499/2023.15169.PEX). MISA acknowledges FCT for the Ph.D. grant PRT/BD/154714/2023. AMF, APT, and AFS acknowledge FCT for the research contracts CEECIND/00361/2022 (DOI 10.54499/2022.00361.CEECIND/CP1720/CT002), CEECIND/01867/2020, and CEECINSTLA/00002/2022, respectively.