Preparation method and product of fermentation broth extractive with chymosin activity

The invention discloses a preparation method of a fermentation broth extractive with chymosin activity. The preparation method comprises the following steps of: culturing paenibacillus CGMCC No.8333 under a temperature of 15 to 40 DEG C through a wheat bran culture medium; oscillating to culture for 18 to 120 hours to obtain fermentation broth; centrifuging the fermentation broth; then collecting supernate to obtain the fermentation broth extractive, wherein the extractive shows chymosin activity reaching 6469.72+/-280.65 SU/mL and protease hydrolysis activity reaching 10.54+/-0.65 U/mL; the ratio of the chymosin activity to the protease hydrolysis activity is up to 613.82. With the adoption of the fermentation broth extractive, liquid milk can be curdled within a short time; in addition, nonspecific hydrolysis for casein is low. The fermentation broth extractive with chymosin activity brings high yield in cheese preparation and has a wide application prospect in the original cheese production and processing industry.