Contributors About the editor Preface CHAPTER 1 Functional roles of polyphenol oxidases in plants and fungi Mehdi Kamali Dashtarzhaneh, Valentina Valencia Bernal and Fatemeh Khodadadi Introduction Polyphenol oxidase structure and mechanism Enzymatic activity and reaction mechanisms of polyphenol oxidases Latency and activation of polyphenol oxidases Polyphenol oxidase and browning Polyphenol oxidase functions against biotic stress in plants Polyphenol oxidase function against plant pathogens Polyphenol oxidase function against insect pests Functions of polyphenol oxidases in plants against abiotic stress Biological functions of polyphenol oxidases in plant metabolism synthesis Betalain biosynthesis Aurone biosynthesis Tyrosine and esculetin metabolism Lignan biosynthesis Functions of polyphenol oxidases in fungi Pigmentation and browning Lignin degradation Morphogenesis Fungal defense and interaction Polyphenol oxidase genes and characterization Conclusions References CHAPTER 2 Plant PPO: Production, purification, and activity assays Zhao Li, Kritika Shrestha and Yu Li Introduction Overall PPO structure Structural information on the substrate specificity Previous investigations on plant PPO purification and characterization Crude extraction and purification of PPOs Characterization of plant PPOs Recombinant plant PPOs: Production, purification and characterization Prior investigations into recombinant PPOs Case study: Recombinant production, purification and characterization of grape PPO Conclusions References CHAPTER 3 Laccase and polyphenol oxidase: Biochemistry and biotechnological applications J. Ashwini John, Sana Riaz, S.K. Taihid Ali and Ethiraj Selvarajan Introduction Structure and catalytic site Mechanism of enzyme action Biochemical applications of polyphenol oxidase and laccase Biosensing/biochemical sensing Removal of pollutants Other biotechnological applications Food industry Textile industry Pharmaceutical industry Bioremediation Conclusions and future prospectives References CHAPTER 4 Recent advances in the design of PPO inhibitors Chen Wai Wong, Zhi Zhou Siew, Win Yee Lim and Eric Wei Chiang Chan Introduction Polyphenol oxidase inhibitors in food packaging systems The role of food packaging on enzymatic browning Active packaging as an innovative approach to inhibit enzymatic browning Choice between plant-based and synthetic PPO inhibitors in active packaging Compatibility of plant-based inhibitors with active packaging Polyphenol oxidase inhibitors in cosmeceuticals Role of tyrosinase in melanogenesis Melanogenesis-related dermatological issues Plant-based cosmeceutical PPO inhibitors Delivery systems for plant-based PPO inhibitors Ethical screening methods for melanogenesis inhibition Conclusion References Further reading CHAPTER 5 Reaction mechanism and redox potential of laccase Nabangshu Dev Sharma Introduction - laccase as versatile biocatalysts Basic structural features of laccases Multidomain structure of laccase Active site characteristics Conserved sequential regions Reaction mechanism of laccases and their unique substrate binding cavity Substrate oxidation Distinction between laccases and other MCOs Oxygen reduction mechanism Redox potential of laccases Role of the axial ligand Other impacting factors Relation between redox potential and substrate specificity Laccase engineering and the role of redox mediators Factors influencing laccase activity other than redox potential Conclusion References CHAPTER 6 Laccases: Biological functions and potential applications Lan Huong Le Viet, Tomoko Matsuda and Ivanhoe K.H. Leung Introduction Enzyme structure and reaction Laccase occurrence and characteristics Plant laccases Fungal laccases Bacterial laccases Insect laccases Biological functions of laccases Synthesis and degradation of lignin Pigment formation and polyphenol oxidation Pathogen defence Biological functions of insect laccase Biotechnological and industrial application of laccases Biodegradation and bioremediation Pulp and paper industry Biosensors nanobiotechnology Biofuels Application in the food industry Cosmetic and pharmaceutical manufacturing Conclusions References CHAPTER 7 Challenges and applications of laccase inbioremediation Ohinerau Bonnet, Tumanako Fa’aui, Ivanhoe K.H. Leung, Shan Yi and Wei-Qin Zhuang Introduction Laccase structures and active sites Laccases redox potential and substrate range Benefits and drawbacks of current laccase degradation systems Free laccase systems Laccase-mediator systems Immobilized laccase systems Fungal versus bacterial laccases for biotechnological applications Laccase-assisted bioremediation strategies Dye decolorization of textile effluents Detoxification of pulp and paper mill effluents Pesticides Endocrine-disrupting chemicals Pharmaceuticals Polycyclic aromatic hydrocarbons Challenges associated with the laccase-assisted bioremediation of emerging contaminants and future perspectives Concluding remarks AI disclosure References CHAPTER 8 Immobilization of Laccase for industrial wastewater treatment: Current challenges and future perspectives Komla Alokpa, Vinoth Kumar Vaidyanathan and Hubert Cabana Introduction Laccase-catalyzed oxidation of substrates Laccase mediator system Cross-coupling and polymerization of substrates Immobilization of laccase Adsorption Entrapment/encapsulation Cross-linking Covalent immobilization Multi-enzyme immobilization Combination of laccase-catalyzed oxidation and photocatalysis Factors influencing laccase immobilization Reactor configurations for laccase-based treatment of wastewater Costs and competitiveness of laccase-based treatment of wastewater (Eco)toxicity of immobilization carrier materials Challenges and future outlook Conclusion References CHAPTER 9 In silico bioprospecting and engineering laccases: Methods and applications Ruite Xiang, Martin Floor, Lars H. Østergaard, Kirk M. Schnorr and Victor Guallar Introduction Molecular determinants of reactivity in laccases Characterization of laccase activity. The computational protocol In silico laccase engineering, putting the protocol to work On demand bioprospecting with our computational protocol Keep an eye on AI Property design, not everything is about high catalytic rates Conclusion Acknowledgments References Index

• Examines the fundamental biology of laccase and polyphenol oxidases, research methods, and their uses across industries • Features chapter contributions from leading international experts in the field