Lignocellulose degradation: An overview of fungi and fungal enzymes involved in lignocellulose degradation

Abstract

This review aims to present current knowledge of the fungi involved in lignocellulose degradation with an overview of the various classes of lignocellulose‐acting enzymes engaged in the pretreatment and saccharification step. Fungi have numerous applications and biotechnological potential for various industries including chemicals, fuel, pulp, and paper. The capability of fungi to degrade lignocellulose containing raw materials is due to their highly effective enzymatic system. Along with the hydrolytic enzymes consisting of cellulases and hemicellulases, responsible for polysaccharide degradation, they have a unique nonenzymatic oxidative system which together with ligninolytic enzymes is responsible for lignin modification and degradation. An overview of the enzymes classification is given by the Carbohydrate‐Active enZymes (CAZy) database as the major database for the identification of the lignocellulolytic enzymes by their amino acid sequence similarity. Finally, the recently discovered novel class of recalcitrant polysaccharide degraders‐lytic polysaccharide monooxygenases (LPMOs) are presented, because of these enzymes importance in the cellulose degradation process.

Cultivation of Mushrooms and Their Lignocellulolytic Enzyme Production Through the Utilization of Agro-Industrial Waste

“…Due to the different bonding functions that exist among these polymers, lignocellulose degradation requires the synergistic action of multiple carbohydrate-active enzymes. These are involved in the assembly and breakdown of glycosidic bonds [132][133][134]. The degradation of lignocellulosic biomass is achieved through cooperative activities of hydrolytic and oxidative enzymes [134][135][136], as is shown in Figure 4.…”

Fungi.guru: comparative genomic and transcriptomic database for the Fungi kingdom

“…Many fungi, especially saprobic fungi, obtain energy from decaying organic matter. Their main source of energy comes from digesting decomposing plant material such as cellulose and lignin (43). Basidiomycetous fungi, for example, Coprinopsis cinerea (Cci) (44), are one of the most potent degraders of cellulose as they often grow in environments that are cellulose-abundant, such as dead wood and plants (45,46).…”

Effect of wood residues on the growth of Ganoderma lucidum

“…Wood is a lignocellulosic raw material composed of cellulose, hemicellulose and lignin polymers. The composition and linkages of wood polymers are diverse reflecting the complexity of the wood (Sánchez 2009;Andlar et al 2018). Despite this, several fungi and other microorganisms can decompose lignocellulosic biomass to obtain carbon and energy resources.…”

“…Fungal mechanisms of lignocellulose decomposition are diverse and complex (Andlar et al 2018). Saprotrophic mushroom species are able to decompose lignocellulosic biomass by producing fungal enzymes, also known as hydrolytic and oxidative enzymes (Sánchez 2009).…”

“…One of the main difficulties in the process of lignocellulose decomposition is the degradation of lignin. Hence, the cultivation of whiterot fungi is presented as an opportunity for the delignification of lignocellulosic biomass (Andlar et al 2018). Wood residues generated by the forestry sector have been previously used as substrates for the cultivation of edible and specialty mushrooms.…”