Isolation And Identification Of Yeasts From Intestine Of Swine And Applied Research

At present，the problem of toxic residues and resistance caused by the a-buse of antibiotics has attracted widespread attention．It is important to finda safe and non-toxic alternatives to antibiotics．Some researches have shownthat certain species of yeast are of great significance to the animals’ physiol-ogical status，growth and reproduction．The experiment collected intestinal c-ontent samples of healthy swines in private farms surrounding Yichang Cityof Hubei Province．Separated and identified yeast from the samples accordingto conventional methods．The result showned that saccharomyces cerevisiae a-nd candida utilis did not exist in the samples．Therefore，the experiment co-ntinued to verify the non-colonization of the yeast and the result is positive-e．The two experimental results shown that yeast can exist in the gut onlyby exogenous specific added．On this basis，one breeding experiment was do-ne to findout the survival rate of four kinds of yeasts(commonly used on th-e market) which were belong to Saccharomyces cerevisiae．The results are a-s follows：1．Yeast was separated and identified from the six sites of the guts of s-wines，including the stomach，duodenum，jejunum，ileum，cecum and colon，the result shown that jejunum had the largest number of live yeasts．2．Randomly selected30strains from the yeasts which were isolated fro-m jejunal contents of the swines，then identified them through physiologicalbiochemical method and26SrDNA of sequence analysis．The result showed t-he yeast species are Saccharomyces，Candida，Pityrosporum，Brettanomyces，Schizoblastosporion，Sporidiobolus，Osporidium，Kloeckera，Leucosporidiu-m and Pichia．We did not find Saccharomyces cerevisiae and Candida utilis．3．We selected six swines that in well condition and the breeding time i-s four weeks．The environmental factors was strictly controlled during the e -xperiment．Feed must be sterilized before fed．Swines were slaughtered afte-r four weeks．From the identification we know that yeast did not exsit in t-he jejunum and cecal contents．It verified that yeast was non-colonization inthe gut of swine．4．We selected six swines that in well condition and the breeding time i-s four weeks，four kinds of yeasts (both Saccharomyces cerevisiae) were ad-ded into the feed in the same proportion．The environmental factors was stri-ctly controlled during the experient to limit the intake of other yeast source-s．Swines were slaughtered after four weeks，we measured the survival of t-he four kinds of yeasts in jejunum and cecal contents by Inter delta analysi-s．This experience could provide a theoretical basis for the applicat-ion of yeast probiotic additives in swine feed．...