Physiology of lignocellulose-deconstructing enzyme production by white-rot basidiomycetes

Vladimir Elisashvili Eva Kachlishvili Mikheil D. Asatiani Eka Metreveli Tamar Khardziani Aza Kobakhidze Violeta Berikashvili Tina Jokharidze
Animal Husbandry and Feed Production, Agricultural University of Georgia, Tbilisi, Georgia

White-rot basidiomycetes (WRB) break down cellulose, hemicelluloses and lignin in wood and other lignocellulosic materials by secreting powerful hydrolytic and oxidative enzyme complexes. However, these fungi show wide intra- and interspecies diversity in their response to particular environmental conditions or developmental stages. In this presentation, the state of the art of lignocellulose-deconstructing enzyme production by wood-rotting basidiomycetes will be presented focusing on their common characteristics and unique properties of individual fungi. Moreover, several approaches and strategies that aim to activate the fungi biosynthetic activity and to increase secretion and yields of lignocellulolytic enzymes will be comprehensively analyzed. Our study underlines that the maximum expression of WRB biosynthetic potential depends on the additive effect of several factors. This approach permitted to achieve the highest laccase (1450 U/ml), MnP (12 U/ml) and lignin peroxidase (0.7 U/ml) activities and as high as 140, 700, and 8 U/ml endoglucanase, xylanase, and filter paper activities, respectively. However, to fully utilize the biosynthetic potential of WRB and to develop technologies of lignocellulose-deconstructing enzyme (individual and/or cocktails) production for industrial purposes, various challenging problems associated with mechanisms of these enzymes synthesis must be solved through collaboration of microbiologists, biochemists and molecular biologists and extensive use of the fungal omics technologies, including genomics, transcriptomics, proteomics, and interactomics.