Conditions Study of Cellulase and Acid Protease Production during the Process of Solid-state Fermentation of Flaxseed Meal

Abstract

Flaxseed meal is a residue byproduct from oil factory; and its abundant nutritive value has not been effectively exploited. Experimental study was conducted on cellulase and acid protease production during the process of solid-state fermentation of flaxseed meal by Asperillus oryzae 3.951. The optimum fermentation condition of HFM and CFM were determined through single-factor experiment. The optimum fermentation condition for production of cellulase and acid protease with HFM as substrate was initial pH of 4.4-4.8, inoculum concentration of 0.5×106 spores /mL, particle size of 250-380 µm, and substrate content of 3 g; while with CFM as substrate was initial pH of 4.8-5.2, inoculum concentration of 0.5×106 spores /mL, substrate content of 3 g, and particle size of 180-250 µm. Under optimum conditions, CFM and HFM produced the highest values of the acid protease activity of 2240U/g and 2189U/g respectively, and the highest cellulase activity of 65.85U/g and 60.22U/g respectively as well. After fermentation content of total sugar and protein increased significantly, the content of cellulose reduced obviously. DSC analysis showed that the thermal stability of fermented flaxseed meal was markedly improved.