Optimization of b- glucosidase enzyme production in shake flask using response surface methodology. Scaling up of b- glucosidase enzyme production from Aspergillus niger NRRL 3122 in Stirred tank bioreactor and rotating fibrous bed bioreactor, purification and characterization of produced enzyme. Application in soy isoflavonoid biotransformartion using commercial b- glucosidase enzyme and the produced beta glucosidase enzyme.