Evaluation of the Probiotic Potential of Microorganisms Isolated from the Intestinal Tract of Cultured Epinephelus akaara

This study focused on isolating and identifying strains from the gut of Epinephelus akaara cultivated in aquaculture facilities on Jeju Island. The aim was to evaluate the potential of utilizing these strains as probiotics for industrial applications. A total of 129 strains were isolated from the gut of E. akaara and screened based on their ability to create a clear zone of 10 mm or more in a preliminary antimicrobial activity test. Twelve strains were selected for further analysis, including bile resistance, acid tolerance at different pH levels, antioxidant activity, antibiotic susceptibility, and biochemical characteristics using the API kit. Through these characteristic experiments, eight strains (G1, G3, G15, G21, B1, B2, B3, B5) were identified as having potential as probiotics. Among these, the B group strains (B1, B2, B3, B5) exhibited significantly higher activity compared to the G group strains (G1, G3, G15, G21). Based on the phylogenetic analysis of the 16S rRNA gene sequences of the selected microorganisms, the strains were named as follows: B1 strain as Lactobacillus paracasei B1, B2 strain as Lactococcus lactis B2, B3 strain as Lactobacillus plantarum B3, B5 strain as Lactococcus lactis subsp. hordniae B5, G1 strain as Bacillus licheniformis G1, G3 strain as Bacillus velezensis G3, G15 strain as Brevibacterium frigoritolerans G15, and G21 strain as Bacillus pumilus G21. KCI Citation Count: 0