Vibrio parahaemolyticus merupakan bakteri halophilic gram negatif dan secara alami terdapat di laut dan dapat menginfeksi kepiting bakau (Scylla serrata), udang windu (Penaeus monodon), kelas bivalvia dan ikan kerapu bebek (Cromileptes altivelis). Penelitian ini bertujuan untuk mengetahui aktivitas daya hambat ekstrak belimbing wuluh (Averrhoa bilimbi L) terhadap bakteri Vibrio parahaemolyticus secara in vitro. Penelitian ini menggunakan metode eksperimental dengan 3 perlakuan dan 3 kali pengulangan. Perlakuan A, B, dan C dengan konsentrasi masing-masing 32 mg/mL, 48 mg/mL, 64 mg/mL. Hasil biakan bakteri dengan pengenceran 10-1 sampai 10-7, diperoleh koloni yang dihitung dari TPC (Total Plate Count) sekitar 1,62×10-6 CFU/mL, sementara uji fitokimia, ekstrak daun belimbing wuluh (A. bilimbi L.) positif mengandung senyawa aktif, seperti flavonoid, alkaloid, steroid, tanin, saponin, dan fenol. Hasil daya hambat terbaik pada uji in vitro, yaitu pada konsentrasi ekstrak 64 mg/mL dengan zona hambat 15,33±0,84 mm menunjukkan ekstrak daun belimbing wuluh dapat menghambat pertumbuhan bakteri Vibrio parahaemolyticus.
Kata kunci: Belimbing Wuluh, In Vitro, Vibrio parahaemolytics

Vibrio parahaemolyticus is a gram-negative halophilic bacterium that naturally occurs in the sea and can infect mangrove crabs (Scylla serrata), tiger prawns (Penaeus monodon), class bivalves and grouper duck fish (Cromileptes altivelis). This study aims to determine the inhibitory activity of star fruit extract (Averrhoa bilimbi L) against Vibrio parahaemolyticus bacteria in vitro. The study used an experimental method with 3 treatments and 3 repetitions. Treatment A, B, and C with a concentration of 32 mg/mL, 48 mg/mL, 64 mg/mL, respectively. The results of bacterial culture with a dilution of 10-1 to 10-7, obtained colonies calculated from the TPC (Total Plate Count) of about 1.62×10-6 CFU/mL, while the phytochemical test, leaf extract of starfruit (A. bilimbi L.) positive contains active compounds, such as flavonoids, alkaloids, steroids, tannins, saponins, and phenols. The results of the best inhibition in the in vitro test, namely the extract concentration of 64 mg/mL with an inhibition zone of 15.33±0.84 mm, showed that starfruit leaf extract could inhibit the growth of Vibrio parahaemolyticus bacteria. Keywords: Belimbing Wuluh, In Vitro, Vibrio parahaemolyticus