Isolasi, Seleksi, dan Identifikasi Bakteri Kandidat Probiotik Potensial untuk Penghambatan Patogen Aeromonas hydrophila
Abstract
Aeromonas hydrophila merupakan bakteri patogen penyebab penyakit Motile Aeromonas Septicaemia (MAS) yang menyerang ikan air tawar. Salah satu solusi pengendalian penyakit MAS adalah melalui aplikasi probiotik. Penelitian ini bertujuan mendapatkan isolat kandidat probiotik potensial terbaik dari benih ikan lele Sangkuriang dan lingkungan budidayanya. Penelitian dilakukan secara eksperimental menggunakan Rancangan Acak Lengkap (RAL) dengan 9 perlakuan isolat bakteri kandidat probiotik dan 2 ulangan dalam uji antagonistik in vitro (kultur bersama) serta, 3 perlakuan isolat bakteri kandidat dan 3 ulangan dalam uji patogenisitas. Hasil penelitian berhasil mendapatkan 81 isolat kandidat probiotik dengan 9 isolat memiliki aktivitas enzim terbesar. Uji antagonistik in vitro dengan metode kultur bersama didapatkan 3 isolat terbaik dari ikan lele dengan kode isolat L13, L22 dan L8. Ketiga isolat tersebut kemudian diuji sifat patogenisitasnya untuk mendapatkan kandidat probiotik terpilih. Isolat L22 merupakan bakteri kandidat probiotik terpilih dengan aktivitas enzimatis, aktivitas antagonistik terhadap A. hydrophila dan tidak bersifat patogen terhadap benih ikan lele. Aeromonas hydrophila is one of the pathogenic bacteria causing Motile Aeromonas Septicemia (MAS) disease that infects freshwater fish. One of the solutions to control MAS disease is through the application of probiotics. This research aimed to obtain the best potential probiotic candidate isolates from Sangkuriang catfish fry and their culture environment. The study was conducted experimentally using a Completely Randomized Design (CRD) with 9 treatments of probiotic candidate bacterial isolates and 2 replications in the in vitro antagonistic test (co-culture) and, 3 treatments probiotic candidate bacterial isolates and and 3 replications in the pathogenicity test. The results of the study succeeded in obtaining 81 isolates of probiotic candidates with 9 isolates having the greatest enzyme activity. In vitro antagonistic test using the co-culture method found the 3 best isolates with codes L13, L22 and L8. The three isolates were then tested for their pathogenicity to get the selected probiotic candidate. Isolate L22 is a selected probiotic candidate bacteria that has enzymatic activity, antagonistic activity against the pathogen A. hydrophila and is not pathogenic to catfish fry.