The Selection And Identification Of Lactobacillus Plantarum And The Research Of Its Preparation Technology

Lactic acid bacteria is a type of bacteria closely related with and plays animportant role in people’s daily life. Some foods such as sauerkraut, yogurt, cheese andother foods rich in lactic acid bacteria. With the in-depth study of lactic acid bacteria,lactic acid bacteria have been found with many healthful effects. Lactobacillusplantarum is a type of lactic acid bacteria with probiotic potential, is widely used infood and feed industry. Some bacteriocin and organic acids produced by Lactotacillusplantarum can inhibit various pathogens.Lactobacillus plantarum can isloate from sauerkraut, pickles, fruits, vegetables,sausages and other foods. They are of different traits, judged by acid andantimicrobial-resistance and other indicators, we isolated an strains of Lactobacillusplantarum named Lac-3with preferred traits, has a strong ability to produce acid,inhibit E. coli, Staphylococcus aureus, resistance to acid and alkali, able to survive inhigh concentrations of choline salt, there is still alive bacteria after treatment withartificial gastric juice for4h, after8h artificial intestinal fluid handling, the survivalrate close to90%, can be used as a leavening agent or feed additives.Choose Lac-3as the experimental bacteria,With cheap carbon source, nitrogensource, buffer salt, growth factor to replace and optimize the correspondingcomponents of MRS culture medium.We obtain a kind of high efficient bacteriaculture medium suitable for Lac-3.Its composition is, sucrose21.8g/L, soybean meal+peptone (2:1)25g/L, growth factor158.5mL/L, CaCO31g/L and NaAc5g/L,manganese sulfate0.35g/L, magnesium sulfate,0.28g/L.Lac-3was cultured withthis culture medium under its best culture condition for24h, the OD600can reach to5.94, which is same as MRS medium.Sodium alginate is cheap,with good biocompatibility, it is the most commonlymaterias be used in capsules.By optimizing the preparation of sodium alginatemicrocapsule,we obtained microcapsule with strong mechanical strength, good shape,the embedding rate is high.In order to improve the resistance of the capsule and extendthe storage period, add a layer of chitosan coating on the surface, at the same time,adding skimmed milk powder as a protectant to core material.Finally, the doublecapsule, bacteria embedding rate surpasses80%, survival rate reached more than90% after processing90min in the artificial intestinal juice,4℃storage after3weeks,survival rate can stay more than80%.