Abstract:In order to investigate the application of lactic acid bacteria(LAB) in the microecological
preparation of Carassius auratus , Lactobacillus coryneform W-17 and Enterococcus faecalis B-8 iso?
lated from the intestinal tract of Megalobrama and Hypophthalmichthys molitrix were selected to feed
Carassius auratus. The effects of two strains of lactic acid bacteria on the immune indexes of Caras?
sius auratus and the expression of non-specific immune genes in various organs were studied. Entero?
coccus faecium B-8 at a concentration of 1.0×108
CFU/mL and Lactobacillus coryneformus W-17 at a concentration of 1.0×108 CFU/mL were added to each gram of the feed of Carassius auratus with an initial body mass of (30.0±1.0) g for 4 weeks. ELISA method was used to detect the contents of IL1β,TNF-α, IL-10, IFN-γ and IgM. RNA from heart,liver,spleen,kidney,and intestine of Carassius
auratus was extracted for RT-PCR to measure the expression levels of IL-1β, TNF-α, IL-10 andIFN-γ. The results showed that at 28 days of immunization, the levels of non-specific antibodies in
the serum of the lactic acid bacteria group were higher than the control group, and those of Enterococ?
cus faecalis B-8 group were higher than those of Lactobacillus coryneform W-17 group.The expres?
sion levels of non-specific immune genes in each organ of the lactic acid bacteria group were signifi?
cantly higher than the control group, and the expression levels of non-specific immune genes in each
organ of Enterococcus faecalis B-8 group were higher than those of Lactobacillus coryneform W-17
group.This indicates that the Enterococcus faecium B-8 can enhance the non-specific immunity of
Carassius auratus to a certain extent,laying a theoretical foundation for the application of lactic acid bacteria in the Carassius auratus breeding industry.