Studies On Breeding And Agents Prepared Core Technology Of Lactobacillus Specific For Vegetable Fermentation

Vegetable fermented is as a kind of traditional health food,which is sour and fresh delicate fragrance,clearness of the pure and unadulterated,frailty is tasty and enjoy in retrospect long,get fed up with solving and open personal status and effect of the stomach,nourishment and health care effect. So vegetable fermented is concerned by more and more people in all countries.The lactobacillus is to ferment vegetable production in of main production germ stub, sieving the appropriation lactobacillus suited for the vegetable ferment is the key to shorten a vegetable to ferment production period, stabilize the product quality and raise the food safety. The key which raises a vegetable to ferment velocity, shortens to keep a hurl type pickles to ferment time and reduces to even keep second nitrate from producing is to raise the live bacteria number of compounds germ powders which is appropriated to ferment vegetable. But dense cultivation is the key to freeze-drying bacteria technology.Main contents discussed in this thesis are as follows:(1) Special Lactobacillus plantarum fermented vegetable breeding technology. Eight lactobacillus strains have been screened from the original culture fluid after certain time of vegetable fermentation. Characterization of morphology and physiochemical properties has confirmed that all of them are lactobacillus. One of the superior bacteria strain Ls03 is bacteria-specific in this thesis, number is NCU116, which was chosen to undergo identification of molecular biology. The above tests verify that the above mentioned belong to the Lactobacillus plantarum category.(2) Studies on determining the quick count of viable Lactobacillus method. This thesis compares Methylene Blue direct count method against Plate Dilution method, Plate Count Agar (PCA) method, GB method, Blood Cell counting plate method, Special Dyeing Count method and Turbidimetry. Out of all the comparisons, Methylene Blue direct count method against Plate Dilution method confirms that Lactobacillus-Methylene Blue direct count method is a direct, fast and accurate way to obtain Lactobacillus total viable count. (3) Studies on pretreatment technology of freeze-drying for Lactobacillus plantarum NCU116:Broth before centrifugation pH6.0,centrifugal matrix is a saline suspension, centrifugal conditions is 4000rmp/min 15min,bacteria under the mud pre-frozen at -70℃2 hours. when Lactobacillus plantarum NCU116 is exist in this freeze-drying conditions, the agents have the higher activity.(4) Studies on protective agent for Lactobacillus plantarum NCU116.The protective agent formula of the freeze-drying for Lactobacillus plantarum NCU116 was optimized by single factor experiment and a three-factor Box-Behnken design.The optimal formula obtained is skim milk 9.24%, trehalose 4.47% and D-sorbitol 13.42%. Protective agent with this freeze-dried formulation tested, it proves the cell survival rate reach 91.76%±1.82%, more in line with the theoretical prediction.(5) Studies on new technology:when protective agent is 10% skim milk, The Two Vacuum Step Drying Method combining with Vacuum Room Temperature Drying and Vacuum Freeze Drying. The results of experiment show The Two Vacuum Step Drying Method can increase the cell survival rate of freeze drying agents, from 85.59% to 90.47%,and low energy consumption, improve the efficiency of agents prepared.