The Role of Probiotic Bacteria on Controlling Vibriosis in Tiger Grouper Fry (Epinephelus foscoguttatus)

Tiger grouper is one of marine fish commodities well-loved by the community and have high
economic value. Increased production of grouper has stimulated disease infection by virus, bacteria, or parasitic
organism in aquaculture environment this experiment was conducted to evaluate the efficacy of probiotic
bacteria in controlling vibriosis disease in tiger grouper fry. The probiotics feed were isolates K7, K8, T36 and
T41. Administration of probiotics was performed for 28 days and on day 29 challenge test was performed using
immersion method in pathogen Vibrio solution at concentration of 106 CFUmL 1. Population bacteria in the liver
were observed evey six hours for 48 hours. The results showed that the four isolates of probiotic bacteria can
reduce pathogen Vibrio populations in the tiger grouper on liver. The survival rates before challenge test in
the probiotic treatments and control were from 65.00 to 88.33% and 71.67%, respectively. After challenge test,
survival rates in the probiotic treatment and positive control were from 51.67 to 78.33% and 48.33%,
respectively. Growth body weight and length in the probiotic treatments were from 7.28 to 8.42% and 2.94 to
3.28%, respectively, while in control 7.07% and 2.92%, respectively. The administration of probiotics T36
provided the best results compared to other isolates. Addition of probiotics can suppress population of Vibrio
pathogen and incresed the surviral rate of tiger grauoper fry. The use of probiotics can increase the production
of tiger grouper.