Recent advances in the biocatalytic mitigation of emerging pollutants: A comprehensive review

The issue of environmental pollution has been worsened by the emergence of new contaminants whose morphology is yet to be fully understood . Several techniques have been adopted to mitigate the pollution effects of these emerging contaminants, and bioremediation involving plants, microbes, or enzymes has stood out as a cost-effective and eco-friendly approach. Enzyme-mediated bioremediation is a very promising technology as it exhibits better pollutant degradation activity and generates less waste. However, this technology is subject to challenges like temperature, pH, and storage stability, in addition to recycling difficulty as it is arduous to isolate them from the reaction media. To address these challenges, the immobilization of enzymes has been successfully applied to ameliorate the activity, stability, and reusability of enzymes. Although this has significantly increased the uses of enzymes over a wide range of environmental conditions and facilitated the use of smaller bioreactors thereby saving cost, it still comes with additional costs for carriers and immobilization. Additionally, the existing immobilization methods have their individual limitations. This review provides state-of-the-art information to readers focusing on bioremediation using enzymes. Different parameters such as: the sustainability of bio-catalysts, the ecotoxicological evaluation of transformation contaminants, and enzyme groups used were reviewed. The efficacy of free and immobilized enzymes, materials and methods for immobilization, bioreactors used, challenges to large-scale implementation, and future research needs were thoroughly discussed.

Automated summary

The issue of environmental pollution has been worsened by new contaminants whose morphology is not fully understood. Bioremediation involving plants, microbes, or enzymes has emerged as a cost-effective and eco-friendly approach to mitigate the pollution effects of these emerging contaminants. However, enzyme-mediated bioremediation faces challenges such as temperature, pH, storage stability, and recycling difficulty. Immobilization of enzymes has been successfully applied to address these challenges, but it comes with additional costs and limitations. This review provides state-of-the-art information on bioremediation using enzymes, including the sustainability of bio-catalysts, ecotoxicological evaluation, enzyme groups used, and challenges to large-scale implementation.