Isolation and selection of fungi with ligninolytic activity for enzymatic deslignification

The lignin it’s a heterogeneous polymeric compound, made by tree monolignols: ρ-hydroxyphenyl, guaiacyl and syringyl, linked among them in beta C-C and C-O-C joining. The diversity of random links and low polarity make lignin be compounds of difficult removal. In nature, white root fungi are in charge of deslignification by lignolítica activity enzymes: lignin peroxidase (1.11.1.14); manganese peroxidase (1.11.1.13) and laccase (1.10.3.2). Notwithstanding the industry makes a removal of lignin to produce cellulose out of lignocelluloses through chemical and physical treatments mainly for cellulose generating environmental residues. For this reason the purpose of this project was selecting enzymatic extracts from fungi to be profiled as complementary alternative to traditional deslignification.

Lignocellulosic material with white root was collected in a humid forest. A total of 17 basidiomycetes fungi were isolated in a culture media with lignocelluloses as only source of carbon, also were they identified into genera and made solid state fermentation for obtaining enzymatic extracts. The enzymatic extracts was characterized trough oxidation of ABTS for laccase activity; vetratryl alcohol for lignin peroxidase activity and ion malonate formation for manganese peroxidase activity. The total concentration of protein was measure trough Bradford method and phenolic total for Follin-Ciocalteu. According to the results, the best enzymatic extracts with ligninolytic activity were selected.