Cloning,Expression and Characterization of Glucoamylase from Gliocladium roseum Immobilization of Glucoamylase onto the Electrospinning PEI/PVA Composite Nanofiber Membrane via Ionic Adsorption Screening and Identification of a High-yield Glucoamylase Bacteria Electrophoresis separation and MS analysis of proteins in fermentation broth of Poria cocos Isolation, Expression and Identification of Multifunctional Glucoamylase from Marine Streptomyces olivaceus FXJ7.023