Method for high-density culture of ready-to-use lactobacillus plantarum, freeze-dried powder prepared by method and application

Abstract

The invention discloses a method for high-density culture of ready-to-use lactobacillus plantarum, freeze-dried powder prepared by the method and application. The method comprises the following steps: (1) placing freeze-dried powder of lactobacillus plantarum in an MRS culture medium for activation twice to obtain a seed starter, wherein the microbial content of the seed starter is 108-109 CFU / mL; (2) inoculating a high-density culture medium with the seed starter according to the volume ratio of (3-6):100 for fermentation culture at 36-38 DEG C, and collecting fermentation bacterial suspension 18-24 h later; (3) centrifugating the fermentation bacterial suspension at 6000-8000 rpm for 25-35 min, discarding supernatant, washing sediment with sterile saline, and collecting bacterial sludge; (4) adding a composite protective agent to the bacterial sludge according to the volume ratio of the composite protective agent to the bacterial sludge of (2-5): 1, and obtaining bacterial suspension containing the protective agent after uniform mixing; and (5) pre-freezing the bacterial suspension containing the protective agent at -20 DEG C to -65 DEG C for 1.5-6.0 h, and then conducting drying in a vacuum freeze-dryer for 18-24 h to obtain the freeze-dried powder. The viable count of the prepared freeze-dried powder is as high as 1010-1011 cfu / g, the moisture content of the freeze-dried powder is less than 3%, and the freeze-dried powder is not prone to agglomeration, has good rehydration performance and can be widely used.

Description

technical field [0001] The invention relates to a direct injection type high-density cultivation method for plantar lactobacillus, in particular to a high-density cultivation method for plantaractobacillus and the prepared freeze-dried powder and its application. Background technique [0002] The high-density culture technology of lactic acid bacteria avoids the possibility that higher concentrations of initial substrates may inhibit the growth of microorganisms and reduce the final concentration. At present, domestic research on the high-density cultivation of Lactobacillus plantarum is developing, and its industrial application is still in the preliminary stage. Scholars have studied buffer salts and adding chemical neutralizers to promote the growth of lactic acid bacteria, but the concentration of the cultured bacterial suspension is still 10 9 cfu / mL levels. Other scholars have studied cell cycle culture and dialysis culture in order to obtain a large number of lactic...

AI Technical Summary

Problems solved by technology

The conditions of high-density medium, centrifugation, harvest age, protective agent, pre-freezing and other conditions selected by the above technology are not suitable, and the safety evaluation of the obtained strains has not been carried out, resulting in a low number of viable bacteria and the safety of the metabolites of the strains. Unclear issues such as sex and drug resistance

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