ABSTRAKPenelitian ini bertujuan mengkaji ekstrak daun api-api putih (Avicennia marina) untuk menghambat patogen secara in vitro dan in vivo pada post larva udang windu. Daun bakau api-api putih dicincang, dikeringkan dan diekstrak dengan tiga pelarut berbeda, yaitu air, air laut dan etanol. Uji daya hambat secara in vitro dilakukan dengan metode agar disc diffusion (ADD) dan minimal inhibitory concentration (MIC). Uji in vivo pada udang windu PL-8 diberikan secara perendaman, yang selanjutnya diuji tantang dengan Vibrio harveyi dan Saprolegnia sp. Hasil uji in vitro menunjukkan ekstrak A. marina dapat menghambat V. harveyi dan Saprolegnia sp. Uji in vivo terhadap infeksi V. harveyi dan Saprolegnia sp., menunjukkan kelangsungan hidup 60-88% dan 57,33-86,67%, dengan kemampuan melindungi dari infeksi patogen tertinggi 80,80% dan 77,80%. Ekstrak A. marina terbaik yang dapat menghambat mikrob dan melindungi post larva udang dari infeksi patogen adalah ekstrak etanol konsentrasi 1250-1500 ppm, diikuti ekstrak air laut 1500 ppm dan ekstrak air 1500 ppm.Kata-kata kunci: Avicennia marina; patogen; post larva; udang windu
ABSTRACTThe research aims to study potency of Avicennia marina leaf extract to inhibit pathogens in vitro and in vivo on post larvae of tiger prawn. The leaves we re chopped, dried and extracted with water solvents, sea water andethanol. In vitro inhibitory tests were performed using agar disc diffusion (ADD) and minimal inhibitory concentration (MIC) methods. The in vivo test on tiger prawn PL-8 was given by submersion, which then tested with Vibrio harveyi and Saprolegnia sp. The in vitro test showed A. marina extract can inhibit V.harveyi and Saprolegnia sp. In vivo tests of V. harveyi and Saprolegnia sp. infections, showed 60-88% survival and 57.33-86.67%, with protective ability of the highest pathogen infection of 80.80% and 77.80%. The best A. marina extract that can inhibit microbial and protect the tiger prawn from pathogen infection is ethanol extract with concentration 1,250-1,500 ppm, followed by sea water extract 1,500 ppm and water extract 1,500 ppm respectively