Insights into Microbial Enzymatic Biodegradation of Plastics and Microplastics: Technological Updates

The massive usage of synthetic plastics in modern life has led to plastic waste generation, and its accumulation is a key concern for the environment and human health. Therefore, plastic is a growing environmental burden because of its small size, stability, and high recalcitrance, needing urgent advancements in plastic waste management. Plastics combined with cocontaminants, i.e., heavy metals, pharmaceutical toxicants, and other plasticizers, can cause serious environmental issues. Hence, an efficient and scalable method based on enzymes and biotechnological approaches is required for sustainable microplastic degradation. The present review focuses on the advanced and emerging biotechnological approaches for plastic and microplastic degradation, i.e., genetic engineering and genome editing tools. The review also discusses the challenges encountered in degradation viz. the depolymerization rate of microplastics and the intrinsic and extrinsic factors, such as degrees of crystallinity, chemical structure, functional group, and molecular weight. Furthermore, the insight in this study is useful to the researchers and scientific communities investigating plastic degradation. Thus, future research can be focused on microbial metabolites and improving catalytic efficiency with extrinsic conditions involved in these processes.