Application of Chemometric Methods for the Optimization Secretion of Xylanase by Aspergillus oryzae in Solid State Fermentation and Its Application in the Saccharification of Agro-industrial Waste

In the present work, a complete study of the production of xylanase by solid-state fermentation (SSF) on a residue mixture by the fungus Aspergillus oryzae ATCC 10124 was conducted, examining the optimization of enzyme production, its physicochemical characterization and saccharification. For optimization of enzyme production, two statistical designs were applied to optimize the mixture of waste residues and fermentation parameters. The centroid simplex experimental design was applied to identify the best composition of residues, sugarcane bagasse (SB), rice husk (RS) and cocoa bean shell (CS) demonstrating that a combination of 25% SB, 25% RS and 50% CS was optimal. Box-Behnken experimental design was applied to optimize fermentation factors, humidity, time and temperature, demonstrating that the combination of 55% humidity, 100 h and 25 degrees C was the most effective for obtaining high enzyme titers. After both optimizations, an increase of up to 165% in enzymatic activity was observed compared to non-optimized production. The xylanase produced in this fermentation process showed alkaline characteristics and high thermal stability. The multienzyme extract (ME) was applied directly for the saccharification of agro-industrial residues with satisfactory results for all lignocellulosic residues tested: sugarcane bagasse, rice husk, cocoa husk and peanut husk, highlighting the possibility of a one-step reduction in the enzymatic process. The saccharification using the ME was efficient, without the need for the enzyme purification step. [GRAPHICS] .