Aspergillus awamori endoglucanase-rich supernatant enhances lignocellulosic biomass liquefaction in high-solids enzymatic hydrolysis

Endoglucanases are particularly important in high-solids enzymatic hydrolysis of lignocellulosic biomass due to the operational need to decrease the medium viscosity via liquefaction, alleviating one of the processes' significant hindrances. This study evaluated an endoglucanase-rich supernatant produced by a particular strain of Aspergillus awamori to speed up biomass liquefaction in reactions with 30% solids. Supplementing commercial enzymes with the crude supernatant of A. awamori (Aa) comparatively decreased the media viscosity 10-fold and improved glucose release by 20% after 24 h hydrolysis. The A. awamori supernatant was fractionated by size-exclusion chromatography, and an endoglucanase-rich fraction was identified by liquid chromatography-mass spectrometry. The endoglucanase fraction and the crude Aa supplementations, under comparative conditions to a highly efficient commercial enzyme, resulted in equivalent improvements in medium viscosity and glucose release, indicating that A. awamori endoglucanases are particularly efficient for biomass liquefaction in conditions of high-solids hydrolysis.