The Study On Resistant Characteristics Of Lactobacillus And Bacillus Subtil Is And Their Prebiotic Effects On Piglets And Mice

Five intestinal lactobacilli and a commercial Lactobacillus LGG and an intestinalBacillus subtilis were selected.The resistant characteristics enzyme production ofLactobacillus and Bacillus subtilis and their prebiotic effects on piglets and mice wereevaluated.1．The five intestinal source of lactic acid bacteria and a commercial LactobacillusLGG were studied. The results showed that：there were some differences about the straintolerance of the external factors.The strain of LGG growth rate，acid productioncapability，acid resistance was better than other strains，but its high temperature resistancewas poorer.The survival rate is only0.2%in the65°C for10minï¼›the strain of ZJ614hightemperature resistance and to deal with the survival rate still reached19.2%for20min at65°C，but the OD600only0.55when in the50mg/L Cu culturing12h，the resultsshowed that it was more sensitive to Cuï¼›the strain of ZJ621was a strong acid tolerance，but more sensitive to bile salt，bile salt concentration of0.1%，and cultured for8h survivalrate of only6.7%ï¼›the strain of ZJ623has good production characteristics，but its acidresistance more susceptible to the influence of the time，and cultured for4h and8h oftheir survival greater impact，indicating that its stability is relatively poor. Comprehensiveevaluation，we screened out of the two growth characteristics of the in vitro environment iswell tolerated strain ZJ610and ZJ617.2．The intestinal source Bacillus subtilis was studied. The results showed that：①thestrain in pH3.0nutrient broth for6h，the survival of rate still reached47.5%；②in the bilesalt concentration of0.3%nutrient broth for8h，the survival rate still reached40.4%；③the survival rate still reached33.3%when cultured in90℃for20min；④when the Cuions and Zn ions concentration of500mg/L，the strain growth is equivalent to the controlof107.6%and86.7%；⑤the protease and amylase activity in the culture supernatant ofBacillus subtilis cultured for48h reached to655.2U and1.89U.3．The two intestinal sources Lactobacillus ZJ610and ZJ617and an intestinal sourceBacillus subtilis were selected and fed weaned piglets.We Selected270Duroc×Landrace×Yorkshire weaned piglets and randomly divided into three treatmentgroups，respectively the control group，antibiotic group，mixed probiotics group. Theresults showed that：①after add mixed probiotics to weaned piglets，compared to thecontrol group，final weight，ADG were increased by0.7%，1.7%，ADFI，F/G were reducedby6.0%，7.7%，but the difference was not significant; compared to no antibiotic group， final weight， ADFI， ADG were reduced by3.8%，6.7%，8.0%， F/G increased by1.7%，but the difference was not significant. Diarrhea index，the control group was highestand up to2.97%，mixed probiotics and antibiotic group were2.26%and2.24%.â‘¡Therewas a certain change of bands of the fecal DGGE profiles during different groups.Thenumber of bands in mixed probiotics group （52.2±5.8） more than the antibiotic group（48.0±5.6），less than the control group （57.2±2.9），but the difference was not significant（P>0.05）. The number of control group bands were19.2%，and higher than the antibioticgroup，and to reach the significance level （P <0.05）.The mixed probiotics group diversityindex （1.70±0.05）was higher than the antibiotic group （1.66±0.05），lower than thecontrol group （1.74±0.02）， the difference was not significant （P>0.05），in addition，thecontrol group diversity index was4.8%higher than the antibiotic group，reach to thesignificance level （P<0.05）.â‘¢The mixed probiotics group of Cytokines IL-6，IL-10，IL-12were highest，the control group were the lowest，the three differences treatmentgroups were to reach a significant level （P <0.01）； TNF-α content of antibiotics groupwere significantly higher than the control group and mixed probiotics group，and reach tosignificant level （P<0.01），but there was no significant difference between the mixedprobiotics group and control group （P>0.05）.4．The486-week-old BALB/C female mice were used，10%of the different treatmentswere fed daily morning gavaged of skimmed milk powder0.5ml，repeated gastricperfusion for14dfor14days. E. coli O157： H₇，attack drug group E，F，G，H test0d，7d attack，attack poison amount of0.5ml/containing only E. coli O157：H₇10⁸cfu/ml in10%skimmed milk powder. The results showed that：①the average daily feedconsumption and weight of the mice of each treatment group with the increase in thenumber of test day shave increased gradually，but no significant differences betweengroups.â‘¡Not challenged groups：the control group with the most numbers up to （54.67±5.03），the Lactobacillus group with the least numbers of （41.00±6.08），during the groupsthere were no significant differences （P>0.05）.The diversity index of the control groupwere the highest of （1.69±0.05），the diversity index of the Lactobacillus group and mixedprobiotics group were （1.56±0.06），during the groups there were no significant difference（P>0.05）.â‘¢Challenged groups：the gavaged lactic acid bacteria group with the mostnumber up to（48.00±11.14），challenged Bacillus subtilis group with the least number of（34.00±7.00） between the groups no significant differences （P>0.05）；diversity indexchallenged lactic acid bacteria group （1.66±0.10） and least challenged control groupdiversity index （1.56±0.06），there were no significant differences during the groups （P>0.05）.â‘£Compared to the control group，gavaged lactic acid bacteria and Bacillus subtilisand their mixed probiotics，the IL6，IL10，IL12，TNF-α of serum did not significantly affect （P>0.05）.Challenged with E.coliO₁₅₇：H₇，the above indicators compared to notChallenged group no significant difference （P>0.05）；but after challenged，TNF-αcompared to not gavaged probiotics groups were improved.Compared to control group，gavaged the probiotics increased the control of CD⁴⁺and CD⁸⁺levels，after challenged thecontrol group CD⁴⁺and CD⁸⁺increased，but gavaged probiotics groups decreased.Thespecies had the bigger influence of CD⁴⁺/CD⁸⁺value，when not challenged，gavagedprobiotics reduced the CD⁴⁺/CD⁸⁺value. But when challenged with E.coliO₁₅₇： H₇，compared to not challenged groups，the control group mice，the CD⁴⁺/CD⁸⁺value wasalmost no change，and the gavaged Lactobacillus group was also almost no change，thegavaged Bacillus subtilis reduced by46.2%，but gavaged mixed probiotics group wasincreased by50%.