Evaluation of the potential of bacteriocinogenic probiotic bacteria in nilotic tilapia (Oreochromis niloticus)

• Grant number: 22/05882-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): October 01, 2022
• Effective date (End): September 30, 2023
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Ricardo Pinheiro de Souza Oliveira
• Grantee: Iara Lima Reis
• 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

Currently, tilapia meat is one of the most consumed sources of protein and its demand has grown over the last decades, however, high mortality rates associated with bacterial infections have hampered productivity, representing an obstacle to the growth of the sector. Evidence has shown that the use of antibiotics, the main method associated with the control of bacterial diseases, contributes to the selection of resistant microorganisms. Because of this, alternative biotechnological resources with antimicrobial potential are investigated. Probiotics, especially those belonging to the lactic acid-producing bacteria (LAB) group, have been considered efficient alternatives, as they improve the immunity and development of their hosts and produce metabolites with antimicrobial activity. In this context, the main objective of the present study is to evaluate the effectiveness of bacteriocinogenic strains isolated from an aquatic environment in the probiotic supplementation of Nile tilapia (Oreochromis niloticus). For this purpose, a comparative evaluation will be made in relation to the effects resulting from probiotic supplementation of individual strains and mixtures containing compatible strains. In addition, the protective capacity of the probiotic will also be investigated, when challenging previously healthy fish with the pathogen Streptococcus agalactiae, and in this way, the effect of treated and untreated fish will be compared. Throughout the experiments, zootechnical parameters and histological analyzes of the intestine and liver will be evaluated to measure the impact of the administration of probiotics on the health status of the animal.(AU)