Nanostructured Particles of Wood: A Promising Substrate for the Production of Lignocellulolytic Enzymes by the Wood-Degrading Fungus Lentinus tigrinus

Abstract

The use of wood nanoparticles (NPs) to increase the efficiency of the synthesis of lignolytic and cellulolytic enzymes using the Lentinus tigrinus basidiomycete is proved. It is shown by the laser diffraction technique that the particle size of the main fractions decreases with an increase in the time of dispersion to 40 min and NPs are detected (the particle size of birch is smaller than that of pine). Using laser interference microscopy and dynamic light scattering (DLS), it is demonstrated that the mean NP size of birch wood after 30 min of dispersion corresponds to 160.9 nm, while after 40 min this size is 95.3 nm. During the cultivation of the L. tigrinus fungus on coarse dispersed particles and NPs of wood, it is shown that the maximum lignolytic and cellulolytic activities are observed on the substrate with birch NPs after six days of growth, 528.44 units/mg in the case of laccase, 61.2 units/mg in the case of peroxidase, 4383 units/mg in the case of Mn-peroxidase, and 69.2 units/mg in the case of endoglucanase. A significant enhancement of the synthesis of ligninlytic and cellulolytic enzymes upon cultivation of the L. tigrinus basidiomycete with the NPs is presumably caused by the increase in the total surface area of the substrate for fungus enzymes. In addition, wood NPs can act as inductors of the biosynthesis of enzymes of the lignocellulolytic complex.