A REVIEW ON THE EFFECTS OF PROBIOTICS AS FEED ADDITIVES ON JAPANESE EEL (Anguilla Japonica), STARRY FLOUNDER (Platichthys stellatus) AND RAINBOW TROUT (Oncorhynchus mykiss)  

Sungchul C. Bai*, Jin-hyeok Lee, Ali Hamidoghli, Seonghun Won, Seunghan Lee,  Youngjin Park
Dept. of Marine Bio-materials and Aquaculture/
Feeds and Foods Nutrition Research Center (FFNRC)
Pukyong Nat'l University, Busan 608-737, Rep. of Korea
Corresponding author: scbai@pknu.ac.kr
 

Aquaculture industry has become a vital economic activity securing protein production in several countries. Along with the fast expansion and intensification of aquaculture, emergence of large varieties of pathogenic diseases are considered limiting impediments. On the other hand, the excessive treatments of antibiotics has caused the appearance of bacterial resistance strains. In this regards, a series of experiments were conducted to investigate probiotics such as Bacillus subtilis, Lactobacillus plantarum, Bacillus licheniformis and multi-probiotics as feed additives. Results for the first experiment indicated that single (B. subtilis or B. licheniformis; 2 × 109 CFU kg -1 diet) or multi-probiotics (commercial probiotics; 2 × 109 CFU kg -1 diet) had equal beneficial effects as antibiotic replacers in terms of growth performance, non-specific immune responses and disease resistance against Edwardsiella tarda in starry flounder. In the second experiment on rainbow trout, also results showed same beneficial effects of single (B. subtilis, 0.5%) or multi-probiotics (B. subtilis + B. licheniformis, 0.5%) as antibiotic replacers on growth performance, non-specific immune responses and disease resistance. In the third experiment, a compression was made for oral administration of B. subtilis (106, 107 and 108 CFU/g diet) and L. plantarum (106, 107 and 108 CFU/g diet). Results showed that B. subtilis (at 108 CFU/g diet) could have more beneficial effects on growth performance, immunological parameters, gut morphology and disease resistance (against Vibrio angulillarum) in Japanese eel. Therefore, according to what was mentioned, it could be concluded that probiotics have the potential as antibiotic replacers while enhancing growth performance and immunity. In addition, application of selective strains of probiotics for specific fish seems to be vital in order to maximize the effectiveness.