Evaluation of the biotechnological application of new bacteriocinogenic probiotic bacteria: effect on health, antimicrobial action and on the preservation of fish meat (Oreochromis niloticus)

Abstract

The growing demand for animal protein for human consumption has led to the intensification of production processes, use of medicines and agricultural technologies. This has made the tilapia culture more susceptible to stress and disease, leading to high mortality rates and economic losses. Probiotics and bacteriocins have emerged in recent years as an effective and eco-friendly alternative to traditional antibiotics and other drugs to improve fish performance and combat fish stress and diseases. They are currently widely used in tilapia culture, leading to significant benefits to the industry and improving tilapia economics and marketing. Therefore, the expected results of this study are primarily focused on the biotechnological application of new strains of bacteriocinogenic probiotic bacteria. Three new probiotic strains with good results against fish and food pathogens in preliminary tests of identification and characterization were chosen for this study. In vitro tests will be performed to evaluate the antimicrobial effect of the BLIS of the isolates against the pathogen Aeromonas hydrophila. Then, the strains will be cultured in a bioreactor and lyophilized. A study of the viability of the strains in the feed manufacturing process will also be carried out. The probiotic strains will be administered daily in the tilapia diet in order to verify the probiotic effect on the health parameters of each bacterium and together (probiotic mix). During the in vivo experiment, the possible protection conferred by the treatments to animals infected by A. hydrophila will also be evaluated. The BLIS produced will be treated, pre-purified and evaluated for its possible application as a biopreservative in tilapia meat.