Chapter 4 White Rot Fungi and Their Enzymes for the Treatment of Industrial Dye Effluents. In:Nath A, Singh YS, Mishra S, Gupta A.(eds)Fungal Biology Recent Advancement in White Biotechnology Through Fungi

Abstract

Ecological monitoring and degradation of phenolics and lignin-based substances from the sludge released by the food, leather, and pharmaceutical industries have become more important in recent years. The use of physical and chemical methods produced excess sludge and recalcitrant chemicals which are not easily degradable. The use of microbial enzymes for the treatment of phenolics-based industrial pollutants has paying attention in recent years because of their ecofriendly nature and higher specificity and efficiency. Among the various enzymes used, fungal laccases and peroxidases (lignin peroxidase (LiP), manganese peroxidase (MnP), and versatile peroxidase (VP) are considered as green catalysts of huge biotechnological importance. Fungi are widely distributed microorganism maintaining saprophytic mode of life and excrete various extracellular enzyme including polyphenol oxidases, laccases, and peroxidases. It is present in various Ascomycetes, Basidiomycetes, Deuteromycetes, and lignin-degrading white-rot fungi. Laccases and peroxidases potentially decolorize and detoxify the industrial effluents containing azo dyes; phenolic, non-phenolic lignin-based compounds; and recalcitrant chemicals. Recently, several advancements in biotechnology used to improve the efficiency and stability of both laccases and peroxidases for various industrial effluent treatment processes. These enzymes simply detoxify the phenolic substances by simple electron transfer reactions. Hence, these enzymes have gained application in detoxification of various industrial effluents, in general paper and pulp, textile, and petrochemical industries, used to eliminate herbicides and pesticides and used as a tool in the design of biosensors. There are various methods such as enzyme nano-catalyst, immobilized enzyme reactors, and whole-cell immobilization that have been used. In this chapter, we summarize the fungal source of laccases and peroxidases, structure, mechanism of action, and environmental applications including industrial waste treatment, and detection and detoxification of pollutants.