Identification of lactobacillus reuteri P2M1 from swine and evaluation of its probiotic function in vitro
Objective The aim of this study was to evaluate the biological characteristics and in vitro probiotic function of Lactobacillus reuteri P2M1 from swine,to determine the probiotic potential of the strain,and explore the possibility of its application in livestock pro-duction.Methods In this study,a strain of lactic acid bacteria(P2M1 strain)isolated from healthy pig feces was biochemically identi-fied,and molecular biological identification was performed using bacterial 16S rDNA sequence PCR amplification and sequencing tech-niques.The growth curve and acid production curve of the strain were drawn to evaluate the tolerance of the strain to acid and bile salts.The sensitivity of the strain to 10 antimicrobial agents was examined.The free radical scavenging ability and extracellular poly-saccharide production of the strain were determined,and then the in vitro safety test was performed to evaluate the safety of the strain to mice.Results The results showed that the strain P2M1 was Lactobacillus reuteri.It has the ability of glycolysis;the logarithmic growth phase was 2～10 h,and the pH was stable between 4.0～4.1 after 20 h.It has good low pH and bile salt tolerance;sensitive to erythromycin(macrolides),amoxicillin,ampicillin(penicillins),cefazolin,cefuroxime(β-lactams);the DPPH,ABTS and hy-droxyl radical scavenging rates of the fermentation supernatant of the strain were significantly higher than those of the intact cell suspen-sion(P<0.05),which were 88.79%,93.52%and 92.15%,respectively.The yield of crude extracellular polysaccharide was 339.82 mg·L-1.No death and organ lesions were observed in mice after intragastric administration of 0.2 mL of live Lactobacillus reu-teri P2M1 solution at a concentration of 1×109 CFU·mL-1 per day for two weeks.Conclusion It is concluded that Lactobacillus reuteri P2M1 has a short logarithmic growth period,rapid growth of cell concentration,high yield of extracellular polysaccharides and good probiotic,antioxidant properties and safety in vitro and can be used as a candidate strain for probiotic preparations.
万方数据
维普
