Study of pretreatment with acid to improve filtration effect of 1, 3-propanediol fermentation broth

Klebsiella pneumoniae TUAC01 is a 1, 3-propanediol producing microorganism which has capsule on the cell surface. Its fermentation broth can not be cleared through flocculation or filtration. After pretreated with acid, the broth can be cleared by filtration and also can be in deposition. The optimal operation conditions are 80-100°C, pH 3.0, 30-60 min. Through filtration the OD650 of the pretreated fermentation decreased to 0.01, reduced by 99.9%; and the viscosity coefficient fell to 0.001 5 Pa·s; the concentration of protein decreased to 0.05 mg/mL, falling by 98%-99%. The method was proved perfect in the large scale workshop experiments, and can be used in pretreatment to clear the fermentation broth by capsule bacterium.