Fungal Assisted Valorisation of Polymeric Lignin: Mechanism, Enzymes and Perspectives

Lignocellulose is considered one of the significant recalcitrant materials and also is difficult to break down because of its complex structure. Different microbes such as bacteria and fungi are responsible for breaking down these complex lignin structures. This article discussed briefly the lignin-degrading bacteria and their critical steps involved in lignin depolymerization. In addition, fungi are regarded as the ideal microorganism for the degradation of lignin because of their highly effective hydrolytic and oxidative enzyme systems for the breakdown of lignocellulosic materials. The white rot fungi, mainly belonging to basidiomycetes, is the main degrader of lignin among various microorganisms. This could be achieved because of the presence of lignolytic enzymes such as laccases, lignin peroxidases, and manganese peroxidases. The significance of the fungi and lignolytic enzyme's role in lignin depolymerization, along with its mechanism and chemical pathways, are emphasized in this article.