BIOTECHNOLOGICAL APPROACHES TO PLASTIC WASTE DEGRADATION

Abstract

Plastic pollution is a persistent global environmental problem driven by massive production of recalcitrant polymers such as polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET). Biotechnological strategies—microbial degradation, enzyme catalysis, fungal decomposition, engineered microbial consortia, and enzyme engineering—offer promising, potentially sustainable routes to degrade or upcycle plastic waste under controlled conditions. Key advances include discovery of PET-degrading bacteria (Ideonella sakaiensis) and PETases, development of engineered PET hydrolases with enhanced activity and thermostability, and evidence that fungi and mixed microbial consortia can attack diverse polymers. However, the intrinsic chemical inertness of polyolefins (PE/PP), variable additives, and inconsistent experimental standards complicate translation from lab demonstrations to scalable processes. Integrated approaches that combine pretreatment (oxidation, UV, thermal), enzyme cocktails, synthetic biology (pathway engineering, secretion systems), and process engineering (bioreactors, immobilized enzymes, coupled upcycling pathways) may overcome these hurdles and produce value-added products (monomers, oligomers, biopolymers). Life-cycle impacts, CO₂ release, and techno-economic feasibility require careful assessment. Continued discovery of novel enzymes, rational enzyme design, and development of robust consortia optimized for mixed-waste streams are essential next steps toward industrially relevant biotechnology solutions for plastic waste management.