Study On Solid-state Fermentation Technology For Nattokinase Production And Preparation Of Freeze-dried Natto Powder

Nattokinase is a fibrinolytic serine enzyme that is produced by Bacillus subtillis natto. Ithas safe and effective, long half-life in the body, no bleeding tendency and so on. Sonattokinase can be developed as a new fibrinolytic medicine. However, the liquidfermentation mode and the downstream separation technology for production of nattokinaseby most factories at present, and lower production capacity at the laboratory level. In recentyears, the solid-state fermentation production mode in the development of enzymepreparation that make production of nattokinase has a realistic significance.Screening of high nattokinase yield for the solid-state fermentation strain. On the basisof single factor experiment, response surface methodology and artificial neural networkcoupling genetic algorithm were used for optimizing solid-state fermentation processparameters of nattokinase, and the optimization effects of the two methods were estimated.The results showed the best conditions were as following: inoculum size4%, initial wateramount55%, soybean content90g/250mL, fermentation temperature36.09℃, sucroseconcentration1.5%, MgSO4·7H2O concentration0.21%, CaCl2concentration0.27%,fermentation time24h. Under these conditions, the maximum nattokinase activity was up to7631.28U/g, which was29.02%higher than that in single factor test. Adopt vacuum freezedrying technology for producing natto power, against natto power producing in theproduction of freeze drying and crushing methods. The influence of the research work wasfor optimizing producing natto power production process and development to provide thechoice of dosage form technical support. At the same time, the changes of nattokinase weredetermined in simulated gastrointestinal environment, and its main components andbioactive substances were determined. It found that the two aspects of nutrition andbioactive substances content higher than soybean powder raw materials through theanalysis, so the freeze-dried natto power producing can be used as a potential health careproducts for development. Freeze-dried natto power in pharmaceutical producing activesubstances of the storage stability was studied which used accelerated storage stabilitydetermination method. The results showed that the international degree of predicted valueand experimental value was higher at4℃and room temperature, so the method had certainpracticability and accuracy, at the same experimental time was shortened.