Stability of PA-1 pediocin in the presence of choline-based osmolytes derived from phenolic compounds

• Grant number: 20/03204-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2020
• End date: July 31, 2021
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Ricardo Pinheiro de Souza Oliveira
• Grantee: Paulo Roberto Rodrigues Coutinho
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 18/25511-1 - Bioprospecting of bacteriocin-producing bacteria: from culture optimization to the application in animal production systems, AP.TEM

Abstract

The ability to persist in food processing environments and multiply at low temperatures, high concentrations of NaCl and a wide pH range, makes Listeria monocytogenes, a pathogenic microorganism responsible for listeriosis disease, one of the main threats to public health in the world. context of consumption of contaminated food products. Considered the most frequent cause of collection and destruction of meat products and processed foods in general, contamination by L. monocytogenes is responsible for generating enormous financial losses for the food industry. In order to meet food safety standards and contribute to reducing the significant economic losses associated with the rejection and collection of contaminated products, new food preservation protocols and technologies are needed. The pediocin PA-1, peptide with antimicrobial action produced by lactic acid bacteria, is considered one of the most important emerging bioconservatives for the food area, due to its proven antilisteric activity. Despite its enormous potential in combating the increasing increase in listeriosis outbreaks, recorded worldwide, its high cost and its high susceptibility to undergo conversion to less active isoforms when it is oxidized (100 times less activity), has been limiting expanding its use on a large scale. In this context, the present work aims to evaluate the ability of different choline salts derived from phenolic acids (natural, biocompatible and "non-toxic" compounds with high antioxidant activity), to improve the stability of PA-1 pediocin over time different storage conditions. Specifically, it is intended to evaluate the existence of mechanisms of protective action against the oxidation of methionine 31 from pediocin PA-1, either through in vitro approaches, through the evaluation of the profiles of antimicrobial action against L. monocytogenes, or through in silico approaches, using the docking molecular simulation tool. For the stabilizing agents that demonstrate the best results, concentration tests will be performed in order to establish the minimum osmolyte concentration necessary for an effective protection of the antimicrobial activity of PA-1 pediocin. In order to proceed with the evaluation of the cryoprotective properties of the stabilizing agents used, studies contemplating the preservation of antimicrobial activity between sequences of freeze / thaw cycles will be additionally carried out.