Yulistia Budianti Soemarie, Rizki Rahmadi Pratama, Tiana Milanda, Melisa Intan Barliana

Lactococcus garvieae was isolated from the traditional fermented food Wadi Papuyu (Anabas testudineus Bloch) and characterized for its potential as a probiotic candidate. Growth assays demonstrated that L. garvieae could proliferate in MRS medium, reaching cell counts exceeding 107 CFU/mL after 72 h of anaerobic incubation. The isolate exhibited optimal growth at both 30 °C and 37 °C, as indicated by significant increases in absorbance at these temperatures. However, in the bile salt tolerance test using 0.5% (w/v) bile salts, L. garvieae showed a marked decline in growth, with absorbance values decreasing substantially after 24 and 48 h, indicating insufficient bile tolerance. The autoaggregation assay revealed values below 10%, suggesting limited autoaggregation capability and reduced potential for colonization in the gastrointestinal tract. In contrast, the co-aggregation assay showed that L. garvieae was able to coaggregate with pathogenic bacteria such as Escherichia coli, Salmonella spp., and Shigella spp., with co-aggregation percentages exceeding 40% after 5 h. Antimicrobial activity tests demonstrated that L. garvieae produced strong inhibition zones (diameters >10–20 mm and >20 mm) against Gram-positive and Gram-negative pathogenic bacteria. These findings indicate that while L. garvieae exhibits promising antimicrobial activity and co-aggregation ability, its limited bile salt tolerance and autoaggregation capacity are significant constraints in its development as a probiotic candidate.