Harnessing Sustainable Biopolymers: Engineered Alginate-Based Materials for Whole-Cell Environmental Remediation

Escalating environmental pollution caused by persistent chemical contaminants demands the development of efficient and sustainable remediation solutions. Bioremediation offers a promising path, and whole-cell immobilization is a key strategy to enhance its performance by protecting microorganisms from harsh conditions and enabling their reuse. Among various carriers, alginate, a renewable biopolymer derived from seaweed, is an exceptional matrix due to its mild gelation, biocompatibility, and low cost. This review critically examines how the strategic engineering of alginate-based materials overcomes the limitations of the pristine biopolymer. A comprehensive analysis of key modification strategies is provided, including covalent crosslinking, the formation of interpenetrating polymer networks (IPNs) with materials like PVA and chitosan, and the development of advanced composites and hybrids incorporating functional adsorbents such as biochar, clays, and nanomaterials. The review then systematically summarizes recent advancements in the application of these engineered biocatalysts for the remediation of a wide range of pollutants, highlighting their enhanced performance in heavy metal sequestration, degradation of recalcitrant organic pollutants, and removal of industrial dyes. By bridging materials science with environmental biotechnology, this review elucidates the principles for designing next-generation "living catalysts" for robust and effective environmental cleanup.