Eco-Friendly Biocatalysts: Laccase Applications, Innovations, and Future Directions in Environmental Remediation

Laccases, a class of multicopper oxidases found in diverse biological sources, have emerged as key green biocatalysts with significant potential for eco-friendly pollutant degradation. Their ability to drive electron transfer reactions using oxygen, converting pollutants into less harmful products, positions laccases as promising tools for scalable and sustainable treatment of wastewater, soil, and air pollution. This review explores laccase from a translational perspective, tracing its journey from laboratory discovery to real-world applications. Emphasis is placed on recent advances in production optimization, immobilization strategies, and nanotechnology-enabled enhancements that have improved enzyme stability, reusability, and catalytic efficiency under complex field conditions. Applications are critically discussed for both traditional pollutants such as synthetic dyes, phenolics, and pesticides and emerging contaminants, including endocrine-disrupting chemicals, pharmaceuticals, personal care products, microplastic additives, and PFAS. Special attention is given to hybrid systems integrating laccase with advanced oxidation processes, bioelectrochemical systems, and renewable energy-driven reactors to achieve near-complete pollutant mineralization. Challenges such as cost–benefit limitations, limited substrate range without mediators, and regulatory hurdles are evaluated alongside solutions including protein engineering, mediator-free laccase variants, and continuous-flow bioreactors. By consolidating recent mechanistic insights, this study underscores the translational pathways of laccase, highlighting its potential as a cornerstone of next-generation, scalable, and eco-friendly remediation technologies aligned with circular bioeconomy and low-carbon initiatives.