Study On Evaluation Of Probiotic Characteristics Of Entorococcus Faecalis

The experiment was conducted to study the growth characteristics, tolerance to acid and bile and antibacterial activity of Enterococcus faecalis(E.faecalis) in vitro and study the effects of dietary E.faecalis on performance, egg quality, serum antibody level and blood fat of laying hens. The results showed as follows:1Evaluation of probiotic characteristics of E.faecalis in vitroTo investgate the probiotic characteristics of E.faecalis CGMCC1.2135, colonies morphologygrowth characteristics, tolerance to acid and bile and antibacterial activity of Enterococcus faecalis were conducted to evaluation:(1) Enterococcus faecalis colonies and colonical morphologyEnterococcus faecalis on TSA agar culture under37℃for colony morphology after24h:round, white, lustrous surface protrusions, neat edge, spherical.Enterococcus faecalis results of Gram staining:positive, spherical, non-sporing, no capsule, in pairs or short chains.(2) Curve and fermentation of pH growth of Enterococcus faecalisThe growth of E.faecalis in TSB medium entered logarithmic phase after2hours culture and reached the stable stage at8hours; Fermentation liquid pH change was consistent with growth curve, the rapid rise in pH between2H and8h,8h after rising velocity.(3) The acid resistance test of Enterococcus faecalisThe bacterium’s viable counts significantly reduced to2.71×105CFU/mL、.03×107CFU/mL and5.65×107CFU/mLwhen the E.faecalis sustained in artificial gastric juice3hours under pH2,3and4, respectively (P<0.01);(4) Enterococcus faecalis bile salt tolerance testThe viable counts significantly reduced1.46×106CFU/mL and1.37×106CFU/mL when E.faecalis cultured in0.2%and0.3%bile salt medium3hours, respectively(P<0.01);(5) Enterococcus faecalis bacteriostasis testEnterococcus faecalis to Escherichia coli O1and O78were mixed with cultured for10h, the number of live bacteria isolated were significantly higher than that of live bacteria mixed culture of number (P<0.01), showed significant inhibitory effect.2Evaluation of probiotic characteristics of E.faecalis in vivo Four hundred and fifty Hy-Line brown laying hens aged137days were randomly allocated into5groups with6replicates per group and15birds per replicate. Laying hens in control group were fed with a basal diet, and those in trial groups were fed with the basal diet supplemented with1.0×104,1.0×106,1.0×108and1.0×1010CFU/g E.faecalis, respectively. The experiment lasted for8weeks (56days). The results showed as follows:(1) There was no significant effects of E. faecalis on laying rate, average egg weight, egg mass, average daily feed intake and feed/egg ratio (P>0.05);(2) Dietary1.0×104and1.0×1010CFU/g E.faecalis reduced albumen height and haugh unit(P<0.05),1.0×104CFU/g E.faecalis significantly induced the shell strength and eggshell thickness in eight weeks(P<0.05),1.0×1010CFU/g E.faecalis had no significant effects on the shell strength and eggshell thickness like the supplementation of1.0×106and1.0×108CFU/g E.faecalis (P>0.05), dietary1.0×104to1.0×1010CFU/g E.faecalis significantly increased the yolk color (P<0.05or P<0.05);(3) Dietary1.0×104to1.0×108CFU/g E.faecalis significantly increased serum IgA level on day21or28, but only1.0×108CFU/g E.faecalis significantly increased the antibody titer to Newcastle diease, and1.0×1010CFU/g E.faecalis significantly reduced the antibody titer to Newcastle diease on day;(4) Dietary1.0×104to1.0×1010CFU/g E.faecalis significantly reduced serum total cholesterol on day56(P<0.05), but had no significant effects on serum triglycerdes like the supplementation of1.0×1010CFU/g E.faecalis(P>0.05);1.0×104,1.0×108and1.0×1010CFU/g E.faecalis reduced serum triglycerdes to a certain extent on day112(P>0.05), but had no significant effects on serum total cholesterol like the supplementation of1.0×106CFU/g E.faecalis (P>0.05).Conculson:It is concluded that E.faecalis growed fastly and could survive in the gastrointestinal tract and inhibit the growth of Escherichia coli to some extent which was appropriate for a production strains of probiotics. E.faecalis had no significant effects on performance, can egg quality, and increase the yolk color and reduce serum total cholesterol and triglycerdes.