Method for preparing nattokinase by liquid fermentation method

Abstract

The invention discloses a method for preparing nattokinase by a liquid fermentation method. The method comprises strain activation, culture medium preparation, seed preparation, inoculation, temperature change fermentation and post-treatment. The method combines strain activation, culture medium preparation, seed preparation, inoculation, fermentation and post-treatment. The whole process is carried out in a clean or sterile environment. The method does not produce escape, overflow, dropping and leakage and satisfies GMP requirements. Compared with the traditional method, the method provided by the invention utilizes an ingenious multi-component medium design and provides a good material basis for growth of nattokinase production bacteria. Through use of a surfactant, nattokinase production and secretion are significantly improved. Through use of the temperature change fermentation method and process, a nattokinase yield is improved by 6-38%. The method has reasonable and advanced processes, is suitable for expanding reproduction, significantly improves a yield and product quality, is environmentally friendly and can be widely used for research and development of nattokinase and other related products.

Description

technical field [0001] The invention belongs to the field of bioengineering and technology, and in particular relates to a method for preparing nattokinase by a liquid state fermentation method. Background technique [0002] Natto is the traditional fermented soybean food that Japanese people love most. Nattokinase (NK) is a kind of protease with various biological activities prepared by fermenting soybean. It has been studied extensively and deeply. Modern scientific research has shown that its structure is a linear amino acid chain without space folding, and its characteristic substrate is fibrin. The fibrinolytic activity is greater than that of plasmin, and the molecular weight is much smaller than that of urokinase and lumbrokinase, and can be absorbed by the intestine. According to reports, nattokinase can effectively dissolve thrombus, and also has various physiological functions such as reducing blood viscosity, inhibiting platelet coagulation, lowering blood fat an...

AI Technical Summary

Problems solved by technology

The classic method used to produce nattokinase is to use soybeans as raw materials, soak, cook, cool down, inoculate and then ferment in an open environment, but the internal bacteria of soybeans are not easy to grow, and the yield will naturally not be too high; CN102586141B Disclosed is a liquid fermentation method using soybean cooking water as the main raw material and supplemented with two kinds of inorganic salts as the medium. In this case, the utilization rate of raw materials is inevitably too low; The method for nattokinase; CN106085991A discloses a method for preparing nattokinase by solid-state fermentation, which provides a method for preparing nattokinase with peanut meal as the main raw material; although the above-mentioned patents provide various The selection of raw materials has made a certain contribution to the improvement of enzyme production, but the pretreatment of raw materials is generally insufficient, the nutrient components of the medium used are not balanced or insufficient, the utilization rate of raw materials is low, and the optimization of fermentation process is insufficient or needs to be improved. The growth of microorganisms is not very vigorous, and the efficiency of enzyme production is not high

Another more important problem is that most of the culture medium raw materials used in traditional methods are mainly composed of extensive raw materials or microbial culture medium, supplemented by inorganic salts. Considering the low cost of raw materials, it is more important for the safety of raw materials. Insufficient consideration of safety, resulting in relatively large safety hazards in the obtained product, basically cannot be directly eaten or applied as a product