WELLINGTON M. MEJIA AND LUSTINA P. LAPIE
Abstract
This study aimed to isolate, characterize and identify probiotic organisms present in the gut of milkfish. Specifically, it sought to answer the questions on: the types of bacteria isolated from the gut of milkfish, isolated bacteria that would manifest the probiotic characteristics in vitro and the identification of the top two probiotic organisms. Bacteria from the gastrointestinal tract of the milkfish (Chanos chanos) were isolated and screened for their potential probiotic properties against some of the freshwater fish pathogens. A total of five isolates based on colony dominance and morphology were selected and tested against Vibrio harveyi and Aeromonas hydrophila in antimicrobic sensitivity testing. Among the five isolates, two of them have shown inhibition against V. harveyi, but none against A. hydrophila. The two unknown isolates were identified as Bacillus subtilis and Bacillus sphaericus based on their phenotypic characteristics observed and identification key. This study showed the potential of bacteria isolated from the gut of C. chanos to act as a possible control agents against V. harveyi, and boost the host immune system against the said fish pathogen.