Expression of Aspergillus niger Glucose Oxidase Gene in Pichia pastoris SMD1168

Abstract:

Aspergillus niger glucose oxidase（GOD） was expressed in Pichia pastoris SMD1168 with the alcohol oxidase gene promoter（AOX1）.A gene of glucose oxidase from Aspergillus niger PCTC was cloned.The gene was fused to the pPICZαA plasmid which had the alcohol oxidase gene promoter（AOX1） and expressed in Pichia pastoris SMD1168.After screening by zeocin gradient resistance plate ，shake culture，and the SDS-PAGE analysis of proteins in the culture，one strain was obtained，which gave the higest enzyme activity（1.12 U/mL） after one day induction by 1% methanol.Through the optimization of the shake flask experiments ，the highest enzyme activity of 32 U/mL was achieved in the flask by induction for 7 d under optimal conditions（30 ℃，200 r/min，pH 5 and 1.5% methanol）.