The Tolerance Of Bacillus Licheniformis SXAU08 And Its Effect On The Intestinal Flora Of Mice

The prohibition of growth-promoting drug feed additives has promoted the rapid development of the probiotic industry,and there are few commercialized probiotics in my country.Bacillus show great potential due to the resistance of its spores to heat,p H and other environmental factors.The tolerance and effectiveness of strains are essential,and the identification of its probiotic characteristics is necessary before commercialization.According to the specific requirements of probiotics,this test studied the tolerance of a Bacillus licheniformis SXAU08 with broad-spectrum antibacterial activity isolated and stored in the laboratory and its effect on the intestinal flora of mice.The specific research content and results are as follows:(1)Using spectrophotometry and Oxford cup method to study the tolerance of Bacillus licheniformis SXAU08,the experimental results show that the strain has resistance of high temperature,high salt and intestinal digestive enzymes.At the same time,it has a high hydrophobic and self-polymerization,and has a certain sensitivity to common antimicrobial drugs for animal use.(2)Using mice as an animal model,the effects of Bacillus licheniformis SXAU08 on the length of intestinal villi,crypt depth and intestinal flora were studied.The results showed that the physiological status of the mice in each group was normal during the 30-day test period,and there was no death;there were no eye changes after anatomy,no pathological changes were observed in the intestinal section,and the blood routine and serum biochemical indicators were normal;the mice in the test group increased in body size.The weight was higher than the control group,and the daily feed intake and feed-to-weight ratio were lower than the control group.Compared with the control group,the T-SOD activity of the low and high dose groups increased,and the AKP activity of the test group was significantly increased(P<0.05),the LZM content in the middle-dose group was significantly increased(P<0.05);compared with the control group,the length of duodenal villi in the low-dose group was significantly increased(P<0.05),and the crypt depth and V/C value were not significant Sexual difference;the duodenal fluff length and V/C values increased significantly in both the medium and high dose groups(P<0.01)and the hidden socket depth(P<0.01).Compared with the control group,in the high-dose group,there was a significant increase in jejunum and cecal Lactobacillus,and a significant decrease in Trichinella.It can be seen that Bacillus licheniformis SXAU08 has high safety,which can improve the growth performance of mice,improve intestinal morphology,and increase the abundance and diversity of intestinal flora.In summary,Bacillus licheniformis SXAU08 is well tolerated and increases the V/C value of mice,the diversity of intestinal flora and the abundance of intestinal Lactobacillus.These features give Bacillus licheniformis SXAU08 the potential for probiotic development.