Application of White-Rot Fungi in Transformation, Detoxification, or Revalorization of Agriculture Wastes: Role of Laccase in the Processes

Abstract

In nature, an enormous quantity of lignocellulose material exists but only a small fraction is valorized, most remaining as waste. Promoting the principle of sustainable and environmentally friendly development, lignocellulose could be transformed through tailor-made biotechnological procedures into value-added natural products for use in animal feed or by the pharmaceutical, chemical, and biofuel industries. White-rot basidiomycetes have developed strategies to efficiently depolymerize and mineralize lignin, the barrier that protects cellulose and hemicellulose from microbial attack, and they represent a feasible option in the treatment of plant biomass and agricultural waste. The extracellular oxidoreductases, laccases, and peroxidases, secreted by these fungi play an essential role in the process. Although laccases have lower redox potential, the expanded role of these enzymes on nonphenolic compounds, in the presence of a low-molecular-mass mediator, as well as their utilization of oxygen, a nonlimited electron acceptor for their catalytic activity, makes them more suitable for industrial and environmental purposes. In this article, we discuss recent progress that has been made in employing white-rot basidiomycetous fungi in biotechnological applications for transforming agricultural waste, as well as for degrading recalcitrant compounds which cause environmental problems. We also focus on the role of laccases in the processes of revalorization, bioremediation, and detoxification of wastes and wastewater.