Degradation of polyethylene terephthalate by microorganisms and their enzymes: A review of experimental and in silico research.

Polyethylene terephthalate (PET) is a petroleum-derived plastic that raises environmental concerns due to its contamination of marine and terrestrial ecosystems. This review summarizes experimental research conducted to assess PET degradation by microorganisms and their enzymes, as well as their associated biodegradation mechanisms. In silico studies on PET biodegradation are also discussed. Studies have investigated PET biodegradation using wild-type microorganisms (bacteria, fungi, algae), isolated or engineered enzymes, wild consortia, and genetically modified microorganisms or consortia. Over the past ten years, approximately 30 bacterial genera (e.g., Bacillus, Ideonella, Pseudomonas), and 15 fungal genera (e.g., Fusarium, Trichoderma, Alternaria) have been studied for PET biodegradation due to their production of predominantly hydrolase enzymes. Wild consortia and mixed enzyme systems have demonstrated potential for PET degradation. Ideonella sakaiensis, its isolated or modified PETase, and both wild and modified consortia have been extensively studied for PET biodegradation, yielding promising results. Enzymes (e.g., leaf-branch compost cutinase) and their variants have also shown high efficiency in PET biodegradation. In silico simulations of enzyme-PET complexes have proven useful in predicting molecular interactions, complementing experimental approaches, and helping in the design of new enzymes for PET biodegradation. Future research should focus on consortia-based or synergistic enzymatic systems to develop scalable biodegradation techniques. The use of biosurfactant-producing strains is crucial to increase polymer bioavailability and enhance hydrolysis. Additionally, PET pretreatment is important for enhancing its biodegradation. Studying biodegradation pathways is important to understand the metabolic potential of microorganisms involved in PET breakdown, which is essential for its sustainable degradation.