The Antagonistic Effect On Pathogen Of Bacillus Coagulans And The Effects Of It On The Growth And Immunity Of Carassius Auratus Gibelio

Objective:To investigate the characteristics and antagonistic effect on pathogen of Bacillus coagulans and effects of different levels of Bacillus coagulans on juvenile carassius auratus growth and immunity.Methods:The activity of extracellular enzyme、physiological and biochemical characteristics were investigated the characteristics of Bacillus coagulans JSSW-07. The inhibition tests and co-culture tests were used to test the antagonistic effect of several aquatic pathogen of Bacillus coagulans.A 45-day growth experiment was conducted to investigate Bacillus coagulans effect to the growth and immune of juvenile carassius auratus. The fish were randomly divided into three groups:a control group was fed with basal diet, and two treatment groups fed with basal diet supplemented with graded Bacillus coagulans(cell concentration 5.8×108 CFU/g) mass fraction levels(0.1%、0.3%、 0.5%, respectively).Each diet (30 fish) was fed to triplicate groups of juvenile carassius auratus with initial average body weight (17.7±0.07) g.Results:Bacillus coagulans had the antagonistic effect on Aeromonas sobria、Aeromonas hydrophila, which could inhibit the 2 kinds of pathogenic bacteria growth,and Bacillus coagulans had a stronger antagonistic effect on Aeromonas sobria. At the end of feeding trial, weight gain rate (WRG) and specific growth rate (SGR) of fish fed diet Bacillus coagulans were significantly higher than these of the control (P<0.05), while feed conversion rate (FCR) was significantly lower in the group supplemented with Bacillus coagulans(0.3%,0.5%, respectively) (P<0.05).Two test groups of each index had no significantly difference (P>0.05). Bacillus coagulans of different addition each index had no significantly difference (P>0.05). The fish fed 0.1% Bacillus coagulans diet couldn’t significantly increase the growth performance of juvenile carassius auratus.The white blood cell count(WBC)、white blood cell count(RBC)、hemoglobin content(HGB) had no significantly difference (P>0.05) among groups. The fish fed 0.5% Bacillus coagulans diet could significantly improve alkaline phosphatase(ALP)、total protein(TP)、aspartate transaminase (AST) (P<0.05),and the fish fed 0.3% Bacillus coagulans diet could significantly degrade the content of ALP、 alanine transaminase(ALT)(P<0.05). The fish fed 0.1% Bacillus coagulans diet could significantly degrade the content of ALP(P<0.05). No significant differences were observed on glucose(GLU)、total Cholesterol(TC)、total triglyceride(TG) content among the treatment groups(P>0.05).Total antioxidant capacity(T-AOC)、superoxide dismutase(SOD) and fungal catalase(CAT) were significantly improved while the fish fed 0.3%-.0.5% Bacillus coagulans diet(P<0.05), and significantly degraded malondialdehyde(MDA) (P<0.05).The fish fed 0.1%Bacillus coagulans diet could significantly improve fungal catalase(CAT),but the content of SOD and T-AOC hadn’t significantly increased.Conclusion:Bacillus coagulans had antagonistic effect on pathogen. It was suggested that Bacillus coagulans of 0.3% supplemented diet can promote juvenile growth and enhance immune function.