7 Unlocking nature’s remediation arsenal : the role of polyphenol oxidases in efficient and eco-friendly industrial wastewater treatment

Abstract

Phenol and its derivatives have gained considerable attention recently due to their high toxicity, teratogenicity, and mutagenicity. Petroleum refinery wastewater is a significant source of phenolic compounds. However, conventional techniques used to treat these wastewaters have several drawbacks, such as incomplete or inefficient removal of phenols. In contrast, biocatalytic processes have garnered significant attention as they offer sustainable and effective removal of toxins, including phenols, from wastewater. Among various biocatalysts, polyphenol oxidases have emerged as major biocatalytic enzymes. These enzymes contain copper and catalyze the oxidation of specific phenolic substrates to quinones in the presence of molecular oxygen. Polyphenol oxidases have a wide range of applications. In the food industry, they are utilized for cocoa and tea production, enhancing coffee flavor and assessing food quality. In medicine, they find applications in treating phenylketonuria, Parkinson's disease, and leukemia. In environmental technology, they play a crucial role in removing phenolic pollutants from industrial wastewater. In the pharmaceutical industry, polyphenol oxidase-immobilized electrodes differentiate between morphine and codeine. This chapter provides comprehensive details about polyphenol oxidases' structure, biochemical properties, and applications, specifically focusing on their role in wastewater treatment.