Microbial Bioremediation of Microplastic Pollution for a Sustainable Ecosystem and Greener Future: A Review
Pollution by emerging contaminants like microplastic is one of the major environmental concerns. Microplastics have become ubiquitous anthropogenic pollutants of aquatic, terrestrial and atmospheric ecosystems, and can generate considerable ecological and health-related risks. Conventional remediation regimes are widely ineffective, due to the physicochemical recalcitrance of polymer matrices. Recent advances in microbial biotechnology have revealed several contrasting microbial taxa and enzyme systems, which can convert or mineralize synthetic polymers through a variety of pathways of complex biochemistry. This review summarizes the current understanding of microbial–polymer interactions, including surface colonization, biofilm-mediated depolymerization, and intracellular uptake of degradation intermediates. It also discusses recent developments in enzyme engineering, strain optimization employing the CRISPR method, and synthetic biology approaches improving catabolic efficiency. The advent of a variety of multi-omics technologies of metagenomics, transcriptomics, and metabolomics has enabled the characterization of novel hydrolases and oxidoreductases with a high potential catalytic efficiency. Advances in nanobiocatalysis, enzyme immobilization, and bioreactor technology improve the scale-up of these processes. Related molecular developments and environmental applications will promote the application of microbial biotechnology as a selective and sustainable tool for the mitigation of microplastic accumulation and the development of a circular bioeconomy that interacts positively with ecosystem resilience.