Efficacy of Bacillus cereus strain BP‐MBRG/1b and prebiotic fructooligosaccharides dietary supplementation on growth performance and disease resistance of Macrobrachium rosenbergii (De Mann) towards Aeromonas hydrophila AH‐1N

The effects of Bacillus cereus strain BP-MBRG/1b (probiotic), 0.4% fructooligosaccharides (prebiotic) and its combination synbiotic dietary supplementations were evaluated in M. rosenbergii juveniles through feeding trials. After 28 days of feeding, the results showed that the probiotic fed juveniles had the highest specific growth rate (SGR) (1.00 +/- 0.02%/day) compared with the prebiotic (0.42 +/- 0.08%/day) and synbiotic (0.54 +/- 0.08%/day) treatments. The prawns were then challenged with pathogenic Aeromonas hydrophila strain AH-1N via static immersion. No significant differences were observed in terms of mortalities for the first challenge nor in the second challenge for all the treatments. Histological observations of the prawn hepatopancreas in all the treatment groups demonstrated necrosis and sloughing of the cells. Overall, the present result suggested that B. cereus strain BP-MBRG/1b demonstrated enhancement of growth performance in M. rosenbergii compared with prebiotic and synbiotic treatments. However, further investigation is required to study the optimal dosage of the synbiotic treatment (probiotic B. cereus strain BP-MBRG/1b and prebiotic fructooligosaccharides) against A. hydrophila challenged M. rosenbergii.