Biomass, lignocellulolytic enzyme production and lignocellulose degradation patterns by Auricularia auricula during solid state fermentation of corn stalk residues under different pretreatments

Abstract

Current work proposes an innovative substitute cultivation strategy for Auricularia auricula that connects efficient lignocellulose biodegradation of corn stalk by pretreatment with mycelium growth of Auricularia auricula under solid state fermentation. The growth promotion effect of mycelium was as follows: alkali pretreatment > alkali combined with ozone pretreatment > ozone pretreatment > high-temperature water pretreatment (control). The highest cellulose degradation (35.38%) was observed in alkali pretreatment group (P < 0.05), while the maximum lignin loss of 28.10% was reached in the ozone pretreatment group. Correlation analysis showed that both cellulose and lignin could be used as carbon sources to promote mycelium growth, but the effect of cellulose was better. High activities of β-glucosidase (2.92 IU/g) and filter paper enzyme (2.92 IU/g) were observed in alkali pretreatment group on Day 6 and 8, respectively, which were significantly correlated with the change of cellulose degradation rate (P < 0.01).

Keywords: Alkali pretreatment; Auricularia auricula; Corn stalk; Lignocellulose; Solid-state fermentation.