Culture conditions optimization and high cell density fermentation of recombinant bacteria producing heparinaseⅡ from Flavobacterium heparinum

Abstract:

HeparinaseⅡ (HepⅡ) from Flavobacterium heparinum is an enzyme that could specifically cleave certain sequence of heparin and heparan sulfate. In this work, fermentation conditions of recombinant heparinase Ⅱ (His-Hep Ⅱ) producing bacteria were optimized, including initial induction time, inducer (IPTG) concentration, induction temperature and induction time. The optimum conditions were as follows: cultivating recombinant bacteria to exponential prophase under 37 ℃, then adding IPTG to a final concentration of 0.3 g/L, finally cultivating recombinant bacteria under 20 ℃ for 10 h. The total crude enzyme activity reached 570 U/L. Based on these results, high cell density fermentation of recombinant bacteria was studied. The final OD600 could reach 98 and the total crude enzyme activity of His-Hep Ⅱ increased to 9 436 U/L.

Key words:heparinaseⅡ, culture conditions optimization, high cell density fermentation