Microorganisms and enzymes involved in polybutylene adipate terephthalate biodegradation

The European Union aims to achieve climate neutrality, protect the environment, and reduce marine litter, particularly caused by the pollution caused by recalcitrant plastics. The investment in biodegradable solutions as alternatives for conventional plastics is a priority for achieving a circular economy and tackling waste management challenges. However, the introduction of novel plastic blends in the environment must consider their effective biodegradation. Polybutylene adipate terephthalate (PBAT) is one of the most interesting polymers to integrate aliphatic-aromatic copolyesters as alternatives to recalcitrant plastics. Compared to other biodegradable plastics, PBAT offers superior flexibility and thermal stability. PBAT is degradable under industrial composting conditions, at thermophilic temperatures. At lower temperatures in natural environments, biodegradation is very challenging, but recent research has shown novel insights on PBAT biodegradation in a variety of environments. This review gives an overview of PBAT physical and chemical properties and its application in plastic blends and focuses on PBAT biodegradation. We compiled information about the microorganisms and enzymes involved in PBAT biodegradation and the environmental conditions in which the biodegradation occurs. For the first time, this review comprehensively compares enzymatic systems, microbial strains, and soil biodegradation while also identifying methodological limitations in the literature. The information presented herein is important to understand the opportunities and limitations of using PBAT in alternative plastic formulations and will hopefully guide the development of biotechnological solutions for plastic waste decontamination, contributing to building a greener future. KEY POINTS: • The blend of PBAT with other materials, change their biodegradation potential • Identification of the PBAT properties affecting biodegradation • Compilation of the few microorganisms known as PBAT degraders in several environments.