| The objective of this project is to isolation some rabbit digestive tract origined microbial species which can be used as probiotic organisms in rabbit production.Experiments 1: Four cutures, i.e., general MRS, MRS+10％extract of domestic rabbit soft faeces, MRS+10％extract of domestic rabbit hard faeces, and MRS+10％pickle juice were selected as test media. The filtrates of cecum and ileum digesta from weaned and growth rabbit were used as inocula, which were inoculated on the plates by line-scratching technique. The inoculated plates were incubated under aerobic and anaerobic condition at 37℃for 24～48h, respectively. The colonies with apparent difference in colony shape, color and surface texture, etc, as well as aspects under microscopy and after Gram stain were re-isolated further, till organisms with uniform character were got. The isolated microbials were identified according to the apparent aspects and the result of biochemistry test. The result indicated that,(1) The number of microbial colony types on MRS+10％rabbit soft faece extract culture was higher than other ones. That implied that was the most favour medium for rabbit intestine microorganisms growth.(2) Thirty-seven strains of bacteria were isolated including 22 aerobia and 15 anaerobia. Among the aerobia, 2 strains of Escherichia coli, 2 Soiled cocci, 2 Lactobacillus brevis, 2 Citrobacter freundii, 1 Enterococcus spp., 1 Caryophanon spp., 1 Brandt Lactobacillus, 1 Bacillus cereus, 1 Lactobacillus saliva, and 9 unknown strains were identified. Among the anaerobia, 3 strains of Fusobacterium spp., 2 Bifidobacterium, 1 Veillonella cocci, 2 Lactobacillus spp., 2 Leuconostoc spp., 9 Lactis spp., 2 Bacteroid spp., and 2 unknown strains were indentified. (3) Among those identified strains, 13 of them were dominant strains, them were, 2 Solied cocci, 1 Enterococcus spp., 2 Lactobacillus brevis, and 2 unknown strains of aerobia, and 1 Fusobacterium spp., 1 Bifidobacterium spp., 1 Lactobacillus spp., 1 Lactic spp., 1 Leuconostoc spp., and 1 Bacteroid spp. of anaerobia.(4) The population of aerobic microorganisms was significantly higher in cecum than in ileum of weaned rabbit. That of anaerobia was slightly higher. Both aerobia and anaerobia population in growing rabbit cecum were significantly higher than that of ileum.(5) Infusing the live culture of 6 test microorganisms to mice for 6 days had not show any determinable side-effect.Experiments 2: The aspect of growth curve of the 6 selected strains was monitorred under different pH and bile salt concentration. The result demostrated that:(1) Most of strains could reach maximum plateau after 4～6h incubation and begin declining at 16h, except 1 strain of Soiled cocci.(2) The growth of all tested strains were inhibited by acid condition, but all of them could keep alive at pH 2.0 for 12h.(3) The bile salt inhibited the growth of all tested microorganisms severesly, 2％bile salt completely inhibited the growth of all microbials after 2h incubation.(4) The Lactic spp. showed low sensitivity to Benzylpenicillin Sodium, other 5 strains were all sensitive to Kanamycin Sulfate, Neomycin Sulfate, Benzylpenicillin Sodium, Chloramphenicol, Erythromycin, and Streptomycin Sulfate.
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