COMPARATIVE PROTEOMIC ANALISIS IN MIXED-SPECIES BIOFILM (Lactococcus sp. and Lactobacillus sp.) DEVELOPMENT BY 2D-SDS-PHAGE AND LC-MS ANALYSIS.

• Grant number: 15/19827-8
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: January 01, 2016
• End date: December 31, 2016
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Bernadette Dora Gombossy de Melo Franco
• Grantee: Natacha Caballero Gómez
• Supervisor: Said Ennahar
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Université de Strasbourg, France
• Associated to the scholarship: 14/06370-7 - Protective biofilms using lactic acid bacteria, BP.PD

Abstract

The successful application of LAB protective biofilms against patogenic biofilms is based on three strategies: one is the phenomenon of competition between the pathogen and the LAB flora (competition for nutrients and/or for surfaces); another regards at the exclusion of pathogens through their trapping by protective LAB biofilms; and the last consists in the displacement of pathogen biofilms by LAB. The action of the protective biofilm towards pathogens is linked to the biofilm properties. However, little is known about the impact of cellular factors of the constitutive bacteria on the properties and the activity of protective biofilms. Also, nothing is known yet on the expression profile of proteins in mixed species LAB biofilms. These knowledge are of utmost interest, since it can lead to a better understand of LAB biofilms and their applications as bioprotective biofilms, drawing new possibilities to future lines of research. Therefore it is our intention to fill this gap. In the first part of this postdoctoral project are selected new strains of LAB, with bacteriocin-producing activity and natural surfactant properties, to develop interspecific protective biofilms with potential application against pathogenic bacteria. It is also important to highlight that, while the genome of an organism is essentially constant throughout life, protein expression changes in different stages of the cell cycle, but also in response to external factors. To go further in the understanding of LAB physiology in biofilms, we propose to carry out proteomic studies 2D-SDS-PHAGE and LC-MS analysis to determine the differences in protein expression that occur in the different biofilms studied in the first part of the project, developed at FCF-USP.