Production of xylanase, α-l-arabinofuranosidase, β-xylosidase, and β-glucosidase by Aspergillus awamori using the liquid stream from hot-compressed water treatment of sugarcane bagasse

Aiming to decrease the cost of enzymes used to hydrolyze biomass, the liquid stream from the hot-compressed water (HCW) treatment of sugarcane bagasse was used in the growth medium of Aspergillus awamori 2B.361 U2/1. Statistical experimental design was used to determine the HCW¹ temperature and residence time for maximum hemicellulose-derived sugar recovery to the liquid stream. The HCW reactor was fed with 10 % (w/v) bagasse, and the treatment was performed under agitation using an initial pressure of 20 bar (N₂) at 170 °C for 40 min. The HCW liquid stream (23.70 ± 0.30 g/L xylan) was diluted and used as the culture medium carbon source for fungal enzyme production. In growth medium containing 5 g/L xylan at initial pH 5.0, the fungus produced 46 U/mL of xylanase (EC 3.2.1.8), 3.3 U/mL of β-glucosidase (EC 3.2.1.21), 0.24 U/mL of β-xylosidase (EC 3.2.1.37), and 0.6 U/mL of α-l-arabinofuranosidase (EC 3.2.1.55) in the supernatant. The use of a residual hemicellulosic stream would decrease the cost of enzyme production and by extension favors the economics of ethanol production from lignocellulosic biomass.