Expression of Aspergillus niger 9891 Endoinulinase in Pichia pastoris

An endoinulinase gene from Aspergillus niger 9891 (CGMCC0991) has been expressed in Pichia pastoris GS115 using pPIC9 vector. The recombinant endoinulinase was highly expressed and the optimization of the expression in a 7 liter of fermentor has been investigated. In fermented broth, the concentration of protein secreted is 2.15 mg/ml. The activity of endoinulinase is 1501 U/ml with sucrose as substrate and 291 U/ml with inulin as substrate, 105 and 273 times higher than that from the original strain respectively.