Engineering lignin-based antimicrobials: Experimental foundations and data-driven optimization

Lignin is the most abundant naturally occurring phenolic polymers on Earth and represents a largely underutilized renewable resource. Owing to its aromatic-rich architecture, diverse functional groups, and intrinsic antioxidant properties, lignin has attracted increasing attention as a sustainable antimicrobial material. Key strategies for enhancing lignin's antimicrobial performance, such as depolymerization, fractionation, and chemical modification, are comprehensively reviewed and linked to the source and chemistry of lignin. Recent advances in lignin-based antimicrobial materials, including hydrogels, films and coatings, nanomaterials, and polymer composites, are summarized, with applications spanning agricultural, biomedical, and food-related fields. Emerging machine learning, global optimization, and computational approaches for predicting and optimizing the antimicrobial activity of lignin-based materials are highlighted, offering new perspectives in bridging experimental foundation and modeling toolsets. This review provides a framework for mechanism-informed, application-specific, and data-driven design and improvement of lignin-based antimicrobials.