The Acid Soup Of Miao Nationality In Guizhou Province Bacteriocin Of Lab Produced Strain Screening And Preliminary Study

Pickled vegetable has a long history in China,2000 produced over the years in many folk method also has continued the production of more original way, and the main natural fermentation, the acid soup of miao nationality in Guizhou Province is one of the representatives of pickled. The acid soup of miao nationality in Guizhou Province use the original production of fermentation methods, during the fermentation produce a large number of Lactic acid bacteria, it can effectively inhibit food spoilage and pathogenic bacteria, but also has beneficial effects on human health. Bacteriocin produced by Lactic acid bacteria due to a non-toxic,efficient,no residue,no drug-resistant features have been widely applied, and is considered the most effective antibiotics substitute, therefore have been as a hot research.In this experiment, use as the has teatment of diarrhea effect acid soup for research object, and analysis of the microbial flora,producing bacteriocin lactic acid bacteria strain was screened, research to produced bacteriocin during fermentation produce for the biological properties.To find new alternatives to antibiotics, but also for the development of microbial preservatives provide the theoretical basis.1.11 LAB strains was isolated from fermentation products, Combination of morphological and biochemical experiments identified have L.plantarum 6 strains, L.curvatu 1 strain,Lactococcus 1 strain, L.mesenteroides 2 strains,L.bervis 1 strain.2. The 3 strains of yeast isolated, including 2 strains for the Saccharomyces yeast,1 strain Candida yeast.Combination of morphological and biochemical experiments were Identified the Saccharomyces yeast which are Saccharomyces cerevisiae and Saccharomyces rouxii, Candida yeast is Candida parapsilosis. And the 3 strains isolated were identified as acetic acid bacteria Acetobacter genus.3. Using single-layer plate agar diffusion method,5 lactic acid bacteria strains can inhibit which Escherichia coli as indicator bacteria were screened from those isolated 11 strains lactic acid bacterias. The exclusion of acid and hydrogen peroxide after the interference, and then by trypsin digestion, the final re-screening obtain to L6 and L10 strains producing Miao of Guizhou Province Sour pickled middle baeteriocin produced by LAB strain and preliminary study protein with bacteriocin. Based on morphological and biochemical characteristics, and molecular genetic analysis of 16S rDNA, were identified Lactobacillus plantarum.4. Inhibitory effect on the most significant L6 Lactobacillus bacteriocin produced by biological characteristics were studied, the results show that:①L6 to 32h in culture produced bacteriocin when E. coli bacteria inhibitory on maximum diameter, its pH value is also reduced to a minimum and in the stable growth;②The bacteriocin produced by L6 was steady in acid condition and it had good thermal stability, the changed very small diameter of inhibitory bacteria when 121℃20min after treatment, of the acid, alkaline and neutral protease-sensitive;③It could inhibit Staphylococcus aureus ACCC10499,Bacillus cereus ACCC11108,Pseudomomas fluorescent ACCC10042.5. L6 produced bacteriocin of LAB fermentation conditions were optimized, analysis of the culture temperature, culture methods, initial pH, inoculum size, medium carbon and nitrogen sources on the production of bacteriocin. Orthogonal experimental methods obtain the best medium C/N source was:sucrose 2%, yeast extract 2%, soy peptone 2.5%. Inhibitory potency is not optimal from the time of 17.27AU/mL, increase to optimized 90.34 AU/mL, the titer increased 423 percent.6. The product of nitrite content was measured as 5.577mg/Kg, lower than the national food hygiene standard 20mg/Kg.