Enzymatic Hydrolysis of Lignocellulosic Biomass Using an Optimized Enzymatic Cocktail Prepared From Secretomes of Filamentous Fungi Isolated From Amazonian Biodiversity

Abstract

The use of lignocellulosic biomass (LCB) has emerged as one of the main strategies for generating renewable biofuels. For the efficient use of such feedstock, pretreatments are essential. The hydrolysis of cellulose – major component of LCB - demands enzymatic cocktails with improved efficiency to generate fermentable sugars. In this scenario, lignocellulolytic fungi have enormous potential for the development of efficient enzyme platforms. In this study, two enzymatic cocktails were developed for hydrolysis of two lignocellulosic biomasses: industrial cellulose pulp and cassava peel. The solid biomass ratio in relation to the protein content of the enzyme cocktail were performed by experimental design. The optimized cocktail for the hydrolysis of cellulose pulp (AMZ 1) was composed, in protein base, by 43% of Aspergillus sp LMI03 enzyme extract and 57% of T. reesei QM9414, while the optimal enzyme cocktail for cassava peel hydrolysis (AMZ 2) was composed by 50% of Aspergillus sp LMI03 enzyme extract, 25% of the extract of P. citrinum LMI01 and 25% of T. reesei. The ratio between solids and protein loading for AMZ 1 cocktail performance was 52 g/L solids and 30mg protein/g solids, resulting in a hydrolytic efficiency of 93%. For the AMZ 2 cocktail, the hydrolytic efficiency was 78% for an optimized ratio of 78g/L solids and 19mg protein/g solids. These results indicate that cocktails formulated with enzymatic extracts of P. citrinum LMI01, Aspergillus sp LMI03 and T. reesei QM9414 are excellent alternatives for efficient hydrolysis of plant biomass and for other processes that depend on biocatalysis.