Saccharogenic refining of Ginkgo biloba leaf residues using a cost-effective enzyme cocktail prepared by the fungal strain A32 isolated from ancient ginkgo biloba tree

Abstract

To reduce environmental pollution and waste of biomass from Ginkgo biloba leaf residues (GBLRs), we developed a cost-effective enzyme system to hydrolyze GBLRs into available reducing sugars (RS). Biomass characteristics of GBLRs were investigated, which indicated that the acid hydrolyzed fraction was 49.43% of the dry weight of GBLRs. The fraction could be effectively converted into RS by an enzyme cocktail with high polygalacturonase activity without traditionally intricate pretreatment. The strain A32 isolated from the ancient ginkgo soil was used for the production of the enzyme cocktail, and a response surface methodology was used to optimize the enzymatic production. The enzyme cocktail released 87.2% of RS from GBLRs at 35 ℃ for 72 h with 1% (m/v) of loading, and the RS concentration arrived 8.95 ± 0.39 mg/ml with 9% of GBLRs loading. The cost-effective system of self-prepared enzyme cocktail is promising for facilitating GBLRs' bio-based industry.