Isolation,Identification And Probiotic Properties Of Lactobacillus Faecis FZB1

Objective To isolate and identify L.faecis FZB1 strain,and study on the probiotic properties of it.Materials and Methods1.Isolation and identification strain Conserved genes of the Lactobacillus sp.,including 16 S r DNA,rpo A and rec A were cloned and sequenced.Biochemical characteristics of the Lactobacillus sp.were determined using the trace biochemical tubes and routine biochemical test.2.To study on the situation of acid and bile salts tolerance,the carbon source utilization ability,the temperature growth of L.faecis FZB1,as well as investigation the adhesive properties to intestinal epithelial HT-29 cells of L.faecis FZB1,and the inhibitory effect of it on adhere to the pathogen E.coli E57.3.In order to investigate the adhesion and colonization of L.faecis FZB1 strain to the intestinal tract of Balb/c J mice,we used PCR assay to track the fecal samples of Balb/c J mice which fed with or no-fed with L.faecis FZB1.4.To study the correlation between L.faecis FZB1 and the anxiety symptoms on host.The anxiety symptoms in Balb/c J mice were caused by RU24969 injection,then,we used various behavioral equipments to assess it,including Morris water maze,Elevated plus-maze and social interaction test.Results1.In isolation and identification trials,The results showed that the 16 S r DNA sequence of the strain had a high homology(99.2 %)with that of Lactobacillus faecis.Amino acid residues sequencing of Rpo A indicated that the strain was closely related to L.apodemi(91.9 %),L.animalis(91.5 %)and L.murinus(91.5 %).The results of biochemical identification showed that the strain had the same characteristics with those of L.faecis,which was identified as L.faecis FZB1(= CGMCC 10515).2.In carbon source untilization trial,acid and bile salts tolerance trials,The results showed that L.faecis FZB1 was capable of using lactose,growing in p H 3 and 0.4 % taurolithocholic acid sodium,0.08 % sodium cholate,0.15 % poultry bile salt,0.15 %sodium deoxycholate,0.15 % taurocholate chenodeoxycholic acid sodium or 0.06 %bile salt.The result of the temperature growth trial indicated that the strain would grow better under the condition of 37 ??3.L.faecis FZB1 exhibited a strongly adhesion ability to intestinal epithelial HT-29 cells,with adhesion rate 88.7 %,which was 11.8 % higher compared to the control — a standardized strain of L.futsaii YM0097,and through displacement to prevent the adhesion of E.coli E57,the rate of relative displacement was 9.9 %,competition and exclusion would mainly promote the adhesion effect of E.coli E57 on intestinal epithelial cells.4.L.faecis FZB1 could adhere and colonize to the intestinal tract of Babl/c J mice,and the adhesion and colonization time was 13 days.The anxiety symptoms in Balb/c J mice were caused by RU24969 injection,then,we used various behavioral equipments to assess it,including Morris water maze,Elevated plus-maze and social interaction test.The results proved that L.faecis FZB1 would attenuate the anxiety symptoms in Balb/c J mice.Conclusion According to the above research,We found that the separation of Lactobacillus from the egret' s feces was identified as Lactobacillus faecis,this strain had the ability to degrade lactose,tolerate acid,tolerate different concentrations of bile salts from different sources,exhibite a strongly adhesion ability to intestinal epithelial HT-29 cells,adhere and colonize to the intestinal tract of Balb/c J mice,13 days of adhesion and colonization,as well as L.faecis FZB1 could alleviate the anxiety symptoms in Balb/c J mice,L.faecis FZB1 strain would be a novel probiotic for the further developed.