Health beneficial properties of bacteriocins produced by lactic acid bacteria isolated from indigenous fermented products

• Grant number: 24/13311-9
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors
• Effective date (Start): September 01, 2024
• Effective date (End): August 31, 2025
• Field of knowledge: Agronomical Sciences - Food Science and Technology
• Acordo de Cooperação: CNPq
• Principal Investigator: Svetoslav Dimitrov Todorov
• Grantee: Emília Maria França Lima
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 24/01721-8 - Health beneficial properties of bacteriocins produced by lactic acid bacteria isolated from indigenous fermented products, AP.R

Abstract

Lactic acid bacteria (LAB) have been widespread throughout history as important microorganisms used in the fermentation of dairy, meat and vegetable products, playing an important role in the development of flavors and textures. Some examples of genera are Lactobacillus (reclassified into 25 new genera since 2020), Lactococcus, Leuconostoc, Pediococcus and Bifidobacterium. These bacteria are capable of converting substrates into organic acids and producing a wide range of metabolites, including antimicrobial compounds such as bacteriocins, giving them a competitive advantage in interactions with other microorganisms. By definition, bacteriocins are protein compounds that exhibit bactericidal or bacteriostatic activity against genetically related strains. Numerous bacteriocins produced by LAB have already been described and are well known for their activities against pathogens of food origin and clinical importance, being indicated for use as biopreservatives in the food industry, in co-administration with antibiotics and recent studies suggest therapeutic use due to anticancer properties. The objective of this project is to isolate bacteriocin-producing LAB strains from a variety of artisanal foods in Latin America, including indigenous products of plant and animal origin. Physiological, biochemical, biomolecular tests and genetic sequencing will be performed for appropriate identification. Once identified, the strains will be analyzed for safety for administration to humans, including assessment of susceptibility to antibiotics (physiological test), detection of genes related to antibiotic resistance and virulence, hemolytic activity, production of biogenic amines, profile enzymatic and mucin degradation. Next, the bacteriocins will be characterized and partially purified through precipitation with ammonium sulfate and separation of fractions by hydrophobic chromatography. Semi-purified bacteriocins will be characterized for antimicrobial activity against relevant pathogens and will be evaluated for cytotoxicity in Vero cells. Finally, semi-purified bacteriocins will be analyzed in in vitro models for anticancer properties using colorectal epithelial tumor cells and for antiviral properties using herpes, dengue and Zika viruses.