Screening for Antimicrobial Peptides with Potential Application Against Foodborne Gram Negative Pathogens

NON-TECHNICAL SUMMARY: Foodborne diseases cause considerable loss of lives and capital. However, there is a shortage of new preservatives that can be used safely and effectively in food. This project addresses the problem just mentioned by searching for novel and effective preservatives, from beneficial bacteria, that can be used to combat disease causing organisms. The goal is to improved safety of processed food without excessive use of chemical additives. Fresh-like processed foods with enhanced safety is the likely outcome of this work.
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APPROACH: The proposed approach ensures efficient and rapid screening for promising microorganism, and allows dictating the properties of antimicrobial peptides sought. Firstly, a novel colony hybridization screening method will be developed. The method is based on the construction of labeled oligonucleotide probes that target published sequences in anti gram-negative peptides. The probe will be used to detect GRAS microorganisms with a potential to produce similar anti gram-negative peptides. GRAS microorganisms from fermented foods (local and ethnic) will used in these screening trails. Secondly, conventional screening methods for antimicrobial peptides will be improved to minimize the interference of non-proteinaceous antimicrobial metabolites (e.g., lactic acid and hydrogen peroxide) with the results of screening. The improved conventional screening method will be used to verify the validity of screened GRAS microorganisms. In the second phase of the study, we will conduct flask- and fermentor-level fermentation to confirm the production of anti gram-negative peptides by the selected GRAS strains. Suitability of these antimicrobial peptides for food applications will be assessed.