Worldinfish production amounted 45.4 million tonnes in 2022 and Nile tilapia (Oreochromis niloticus) contributed with 7.9%, equivalent to 4.5 million tonnes of the total finfish (FAO, 2022). Demand of this protein source is raising as population is increasing, therefore high stocking densities and stressing conditions are often observed in fish farms, leading to disease outbreaks and the use of conventional antibiotics, raising concerns about bacterial antibiotic resistance and ecological repercussions due to the long life of some chemicals in the environment and the possibility of antibiotic transference resistance genes to another microorganisms in the media. Interest in probiotics research and use as a microbiota modulator alternative, pathogenic antagonistic and a new unicellular protein source, emerging as promising feed options a sustainable solution for aquaculture nutrition and health management has increased. In this study, intestinal and water samples were collected from an (Recirculating Aquaculture System) RAS comprising four tanks located at the Agro-Entrepreneurial and Aquaculture Center of SENA in Fonseca, La Guajira Department. Yeasts were isolated in YPDA (Yeast Peptone Dextrose) agar plates and secreneed. A total of 17 yeast isolates were obtained, among which genera. None of the isolated strains exhibited any hemolytic activity or showing resistance to relevant antifungal agents. Moreover, data on hydrophobicity (>60%) correlated with biofilm formation, and complementary antioxidant activity data obtained through DPPH, ABTS, and Folin-Ciocalteau methods, all exceeding 40% of this capacity compared with controls. Regarding antimicrobial activity, the results indicate inhibitory activity ranging from 75% to 85% against the evaluated pathogens (Streptococcus agalactiae, Aeromonas hydrophila and Edwardsiella anguillarum). Furthermore, these selected morphotypes were found to resist gastric conditions, pH variations and tolerance bile salts.