Sauerkraut Fermentation Broth Of Small Molecular Peptides Extraction, Purification And Antibacterial Test

In the northeast of China, there is a kind of traditional food:pickled cabbage, its color, taste is loved by the public, is indispensable to the table the dish. It is worth mentioning is its preservation time is very long. Thus, we have to think the reason, especially, in the process of their own pickled sauerkraut, the preservation of life can be up to 1.5 years old. Therefore, in order to develop a natural preservative for the purpose, to do the experiment to confirm the composition of its antibacterial preservation. This paper reviews the fermented foods of all kinds of research progress, research the sauerkraut fermentation broth of various compositions, reviews the research progress of all kinds of preservatives, focusing on description of the nisin of domestic and foreign research progress of and small molecule polypeptide extraction, separation and purification of progress. The comparison of nisin and the substance in pickled cabbage. After the experiment proved that vegetable preservative effect is a polypeptide substance in action, so this paper compares the two different kinds of salt, which the peptides were extracted by the salting out method, and further separation and purification and research its antibacterial properties; get the results of this thesis are as follows:1. This study selected 40 ℃ temperature, concentration and volume ratio of for 250:60=4:1 concentration ratio and concentration gradient sauerkraut fermenttationfermentation broth.2. In the single factor experiment were investigated. Effects of time, temperature and salt concentration on the extraction yield, the results of single factor are as follows, ammonium sulfate:extraction time is 2 hours, the concentration of salt was 60%,extraction temperature 4 DEGC reached the maximum value in a single factor extraction volume; sodium chloride:extraction time 2.5 h,60% of salt concentration, extraction temperature 8 degrees reached the maximum amount of extraction of single factor values.3. After single factor experiment, using response surface analysis method was used to optimize the experiment, the optimum extraction conditions were obtained as follows. Ammonium sulfate:extraction time:1.7 h; extraction of salt concentration:49.14%; extraction temperature is 5.67℃; sodium chloride:extraction time:1.85 h; concentration of salt extracted 53.8%; extraction temperature for 7.37℃4. Using the dialysis bag with a molecular weight of 1000, the best dialysis solution was obtained by dialysis and 48 h.5. The application of column chromatography to determine the optimal amount of liquid is 3ml, at a flow rate of 3ml/min, received a total of 80 tube for optimum separation and purification conditions, in the experimental process, respectively, three peak, collecting three peak around two tubes.6. By polyacrylamide electrophoresis experiment to determine the peptide is composed of three parts,3500 Da,7000 Da and 22000 Da.7. after in vitro on Staphylococcus aureus and Escherichia coli antibacterial experiment that the small molecule polypeptide inhibitory effect was better than that of Streptococcus lactis, the bacteriostasis diameter of both are 21.2±0.2 mm and 18.6±0.2 mm, after inhibitory concentration test, confirm the small peptide molecules inhibit the minimum concentration of Staphylococcus aureus 8 mg/mL, the best inhibitory concentration for 16mg/mL. The minimal concentration of the small peptide molecule solution was 12 mg/mL, and the best inhibitory concentration was 16 mg/mL.8. After trypsin treatment after, the sauerkraut fermentation liquid material lost antibacterial activity, further confirm the properties of the protein.