| Probiotics in aquaculture has been redefined as the living microflora who can improve the host and the surrounding environment by improving the microbial flora, feed utilization, host immunity, improving water quality in the surrounding environment, beneficial impact on host organisms. Probiotic can maintain the host micro-ecological balance, improve the health of aquatic animals by strengthening the barrier function in intestinal microflora or by enhancing non-specific immune function; the probiotics in aquaculture research initially focused on juvenile fish,now more focused on fish, shrimp, shellfish, crustaceans, and other live food organisms.In this experiment, the crucian carp as the research object, in the basal diet who has be mixed in different combinations of probiotics research on growth performance, immune function, intestinal microflora, to provide guidance and provide theoretical basis for further study for the application of probiotics in aquaculture. As follows:Selected initial weight 15±0.5 and healthy crucian carp for the test, and randomly placed in 12 glass aquariums (50 cm×50 cm×80 cm) feeding a total of 240, in its basic diet were added 0‰probiotics (A group),1‰preparation of Bacillus subtilis (B group),0.5‰Bacillus subtilis,0.5‰photosynthetic bacteria mixed preparation (C group),0.5‰Bacillus subtilis,0.5‰lactic acid bacteria preparation (D group), each group of three repeat groups, and feed each group of bacterial agents were 2×106 cfu/g at the same concentration level, the circulatory system in the room for a period of 5 weeks in the trial, at 14d,28d,42d Detection of phagocytic leucocytes in each group, bactericidal activity, serum lysozyme activity, serum SOD activity, and Od,42d on the fish in each group were weighed to calculate the growth performance index;to 14d,28d,42d to gut the fish in each group contents, by PCR-DGGE molecular techniques to detect the structure of carp intestinal flora and diversity, and select the common band with the specific bands were cloned and sequenced.Results:Growth performance in the test group B carp weight gain, specific growth rate, feed conversion rate, and the blank group A significant difference (P<0.05), And in 28 days, phagocytic activity, serum SOD was significantly different (P<0.01) the control group A; Test C group 28d,42d when the carp leukocyte phagocytosis, bactericidal activity, serum lysozyme activity, serum SOD activity in group A were significantly different (P<0.05), test group D are higher than the above three indices A, but no experimental results B, C group is good, that different combinations of probiotics can improve the phagocytic activity of carp white blood cells, bactericidal activity and lysozyme activity, and the test group B was better than other test groups.In immune parameters, the experimental group B carp leukocyte phagocytosis, bactericidal activity, serum lysozyme activity, serum SOD activity in various stages of the control group A significant difference (P<0.05), test C group at 28d,42d when the white blood cells of crucian carp phagocytosis, bactericidal activity, serum lysozyme activity, serum SOD activity in group A were significantly different (P<0.05), test group D are higher than the above three indices A, but the results did not experiment B, C group is good, indicating that different combination of probiotics can improve the phagocytic activity of carp white blood cells, bactericidal activity and lysozyme activity, and the test group B was better than other test groups.In the intestinal flora, crucian carp intestinal flora similarity of the experimental group B 85%-91%,88%-93%,92%-100% coefficient higher than the control group A (58%-73%,69%-72%,73%-83%), in the 14d,28d,42d, B group of the fish diversity of bands were 21,27,24.3 are high in the control group 13.3,17.7,20; test C group carp intestinal flora similarity 73%-93%,92%-100%,90%-100% coefficient higher than the control group, but worse than the B group, C group diversity, both bands were 16.3,24,21.3 high in the control group; test D group at all stages of the similarity coefficient and the diversity of bands than the B, C group differences, results showed that:different combinations of probiotics can improve the environment of carp intestinal flora, and the B group was better than C, D group is better.DGGE profiles in this study were selected on the strong similarities in each group and the map on a specific band of the DGGE bands were purified, cloned and sequenced, sequencing results showed that:a strong band for the common E. coli, specific articles with the lactic acid bacteria, Legionella, and not bacteria.
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