Effects of potential probiotic Bacillus cereus EN25 on growth, immunity and disease resistance of juvenile sea cucumber Apostichopus japonicus.

This study was conducted to determine effects of potential probiotic Bacillus cereus EN25 (isolated from mud of sea cucumber culturing water bodies) on growth, immunity and disease resistance against Vibrio splendidus infection in juvenile sea cucumbers Apostichopus japonicus . Animals were respectively fed diets with B. cereus EN25 at 0 (control), 10 5 , 10 7 and 10 9 CFU/g for 30 days. Results showed that dietary B. cereus EN25 had no significant effects on growth, total coelomocytes counts and acid phosphatase activity of A. japonicus ( P > 0.05). Dietary EN25 at 10 7 CFU/g had significantly improved the phagocytosis, respiratory burst activity and total nitric oxide synthase activity of animals ( P < 0.05). Compared to control, dietary EN25 at 10 5 or 10 7 CFU/g had no significant effects on superoxide dismutase activity of A. japonicus ( P > 0.05), whereas dietary EN25 at 10 9 CFU/g had significantly decreased its activity ( P < 0.05). The cumulative mortality after V. splendidus challenge decreased significantly in sea cucumbers fed with EN25 at 10 7 CFU/g ( P < 0.05). The present study confirmed dietary B. cereus EN25 at 10 7 CFU/g could significantly improve immunity and disease resistance in juvenile A. japonicus . [ABSTRACT FROM AUTHOR]