Probe Into The Preservative Effect On Food Of SDLH Antimicrobial Peptides

Antimicrobial peptides, as a kind of new natural preservative, has become a hot issue in study of food additive. At present,most antibacterial activity materials which are separated from microbial metabolic are small molecular weight proteins or polypeptides. In the previous studies, SDLH strain has been separated from the foregut. Fg of Oxya chinensis Thunberg, it has been identified as Enterobacteriaceae, Serratia Bizio and Serratia marcescens with rDNA testing for16seconds. Focusing on the basic requirments of food preservative, this experiment probes the following aspects. Conventional preservative must meet the following requirements. l,the nature of the preservative is more stable. Put the preservative into food, the preservative will keep effective with good stability after a certain period of time.2,Low concentrations preservative must have stronger bacteriostasis.3, the preservative itself should not have exciting odour and peculiar smell.4, Security of the preservative must be guaranteed.Having separated and purified SDLH antibacterial peptides mainly through the DEAE-32and G50, the experiment finally gets pure white tasteless electrophoresis level powder material whose molecular weight is17kd, which provides material for the further physico-chemical properties, toxicity research and preliminary add application. Physico-chemical properties experiment results show that nature of SDLH antimicrobial peptides is more stable and has a broad spectrum bacteriostasis. The experiment mainly adopts MTT method to gauge of SDLH antimicrobial peptides, the results show that they have no cytotoxicity and routine acute toxicity test results show that SDLH antimicrobial peptides have no obvious effects on rat. The greatest usage, the best usage of the SDLH antibacterial peptides in pineapple juice drinks are determined by single factor experiment and orthogonal experiment. The optimum technology and the best formula of combination preservatives which are combined with SDLH antibacterial peptides are also determined. And this kind of preservative can make pineapple juice drinks keep fresh for6days. Given that detailed study of the molecular structure characteristics of SDLH antimicrobial peptides has not done,and a large number of documents show that scientists have not yet reached an agreement on the mechanism of antimicrobial peptides, this experiment can not know the antibacterial mechanism of SDLH antimicrobial peptides. The next steps are mainly study the molecular structure and the toxicity of SDLH antimicrobial peptides. Then try to conjecture the possible operation of SDLH antimicrobial peptides according to the existing mechanism. We believe that SDLH antibacterial peptides will be applied to the food industry as a new type of natural preservative by various means of genetically modify in the future.