Study of Some Parameters which Affect Xylanase Production: Strain Selection, Enzyme Extraction Optimization, and Influence of Drying Conditions

Xylanases are glycosidases mainly responsible for the hydrolysis of beta-1,4 linkages in xylan. Xylanase was produced in this work by solid-state fermentation using agro industrial residues with Aspergillus niger strain, which was screened through qualitative and quantitative methods. Extraction processes with different solvents were evaluated. Solvent volume, time, and agitation speed (shaker) were optimized using statistical designs. Drying studies of the solid fermented material were also conducted in a laboratory oven where the following conditions were applied: 42 degrees C and 50 degrees C for 20 h and 80 degrees C for 1 h; 50 degrees C and 75 degrees C for 6 and 3 h, respectively. Best extraction conditions were 37 mL of solvent composed by NaCl solution (0.9%) with Tween 80 (0.1%) in 3 g of cultured material with agitation at 133 rpm in shaker for 4 min. Highest xylanase activity was 2,327 IU/gdm. The drying at 42 degrees C for 20 h provided a better maintenance of xylanase activity (58% of xylanase activity). (C) KSBB