Fermentation Technique Of Enterococcus Faecium TC3 And Application On The Weaned Piglets

Enterococcus faecium TC3, which was isolated and identified from intestinal of healthy piglets, has been verified its probiotic activity by Xiong Yuanyuan in our laboratory. The optimization of fermentation technique was researched in order to improve the number of live bacteria for the industrial production. To investigate the effects of microbial ecological agent on the performance and the impact of the intestinal flora of weaned piglet, the borth of E. faecium TC3 and Bacillus subtilis and B. subtilis powder were fed to them.Exp.1 The fermentation conditional optimization of E. faecium TC3The growth curve was drawn in the basal fermentation medium. The single-factor tests were conducted to determine the inoculation amount, filling volume, ten kinds of carbon sources, nine kinds of nitrogen sources, and five kinds of buffer systems respectively on the proliferation effect of TC3. The results showed that TC3 arrived at stationary phase when cultured for twelve hours. And the optimal inoculation amount was 1%, the optimal filling volume was 60%; the optimal carbon and nitrogen sources were sucrose and fish meal; the optimal buffer systems was light calcium carbonate.Five factors containing sucrose(X1), yeast extract(X2), fish meal(X3), magnesium sulfate(MgSO4)(X4) and light calcium carbonate(CaCO3)(X5) effects on bacterial multiplication were observed by Plackett-Burman (PB) design. We found three key factors which were sucrose, yeast extract, calcium carbonate; and sucrose and yeast extract were positively, calcium carbonate was negatively. The medium consist with 1.63% sucrose,0.71% yeast extract,1.52% CaCO3,0.5% fish meal,0.01% MgSO4 was defined as the optimum medium for TC3 growth, through the design path of steepest ascent, Box-Behnken combination, and response surface analysis.Exp.2 Application of probiotics fermentation broth on the weaned pigletsTo study the effects of microbial ecological agent on the performance and the impact of the intestinal flora of weaned piglet,160 weaned piglets of three-way cross-bred [Duroc X (Landrace X Large White)] with average 30 day-old were assigned to four groups:fed with basic diet added antibiotic (75 mg chlortetracycline per kilogram)(group Ant), basic diet added antibiotic and broth of E. faecium TC3(group Ant+ E. fac), basic diet added antibiotic and broth of B. subtilis(group Ant+ B. sub.), basic diet added B. subtilis powder and broth of TC3(Pro), respectively. The changes of intestinal flora were analyzed by PCR/DGGE technology during the experiment.The results showed that the performance of the group Ant+ E. fac., Ant+ B. sub. and Pro had not difference with group Ant(P>0.05), while the diarrhea rate had decreased 54.9%,41.4% and 47.1% respectively compared with group Ant, the diarrhea index had decreased 55.1%,26.0% and 51.9%. DGGE profiles of intestinal flora were complicated among the groups after weaning. There were no predominant bands before the experiment and low similarity between individuals. DGGE profiles of group Ant+ E. fac. showed higher similarity between individuals compared with that of group Ant. And there were some common predominant bands found in DGGE profiles of group B. sub. and Pro. It was concluded that there might be some effects on the development and construction of the intestinal flora by the application of the probiotics.