Study on the fermentation conditions and purification of β-glucosidase from Aspergillus niger

To find the conditions of fermentation and purification process of β-glucosidase from Aspergillus niger CICC 2475.The fermentation conditions of β-glucosidase from Aspergillus niger CICC 2475 were optimized by artificial neural network in JMP 7.0.The crude enzyme was precipitated with ammonium sulfate, purified with DEAE-52 anion exchange chromatography and Sephacryl S-300 High resolution, and the enzyme molecular weights were identified by SDS-PAGE. The results showed that, the optimal fermentation conditions were as follows, inoculation amount 11.0%, initial p H5.6, fermentation time 130 h and broth content 70.0 m L, at this point, the enzyme activity reached 118.73 U/m L.The β-glucosidase could be efficiently purify by anion exchange chromatography and gel chromatography, and the enzyme molecular weights were about 1.3 × 105.