Preparation method of lipase

The invention discloses a preparation method of lipase. The preparation method is characterized by using a N.sitophila strain No.17 with collection number of CGMCC No.1836 as the strain, using bran and com gluten meal as main ingredients of a culture medium with the initial pH value of 6.0 and inoculum size of 1%, adding 0.1% of Tween-80 and 0.01% of KCl, carrying out culture at 33 DEG C for 48 hours to obtain fermentation liquor rich in lipase with activity as high as 303.83U/mL, collecting supernatant after centrifuging the fermentation liquor, preparing high-purity lipase by carrying out salting out with ammonium sulfate with the saturation degree of 30%W/V, hydrophobic interaction chromatography with Octyl-Sepharose FF (fast flow) and gel chromatography with Superdex 75 on the supernatant in sequence, and then carrying out freeze drying to prepare lipase freeze-dried powder. The lipase has the molecular weight of about 32000 dalton, has more stable activity when the pH value is 7-9 and the temperature is about 30-40 DEG C, and has the capability of decomposing grease. The preparation method has the beneficial effects that the used strain is safe in source; the enzyme production cycle is shorter; the properties are excellent; the culture raw materials are cheap and accessible; and obtained lipase is exoenzyme, thus being especially beneficial to subsequent separation and purification in preparation.