Study On Probiotic Characteristics Of Lactobacillus Plantarum BLPL03 Isolated From Piglets And Its Synergistic Effect With The Nano Zinc Oxide

Due to nutrient,environmental and psychological stress,weaning piglets are easier to suffer "Early weaning syndrome",which will cause a series of symptoms including inappetence,the damage of intestinal mucosal morphology,disorder of gastrointestinal microbiota and diarrhea.In this study,Lactobacillus plantarum BLPL03 which isolated from healthy piglet faeces,was investigated for its survival capacity(acid and bile salt tolerance,antibiotic susceptibility)and probiotic properties(inhibition on pathogens,adhesion to Caco-2 cell).The results showed that Lactobacillus plantarum BLPL03 was able to survive at pH 2.5 for 6 h and 0.45% bile salt for 12 h,suggesting that it can survive well in the gastrointestinal tract.Lactobacillus plantarum BLPL03 had a broad spectrum against Gram-positive strains(Listeria monocytogenes CMCC 54007 and Satphylococcusaureus CMCC 26003)and Gram-negative strains(Salmonella Typhimurium ATCC 13311 and Escherichia coli O157:H7).The strain showed best inhibitory effect toward Salmonella Typhimurium,followed by Escherichia coli and Listeria monocytogenes.Antibiotic susceptibility tests showed that Lactobacillus plantarum BLPL03 was susceptible to 5 kinds of antibiotics(amoxicillin,erythromycin,chloramphenicol,ampicillin,and cefuroxime)and tolerated to 6 kinds of antibiotics(streptomycin,gentamicin,kanamycin,tetracycline,Polymyxin B,and ciprofloxacin).Then we investigated synergistic effect of the nano zinc oxide and Lactobacillus plantarum BLPL03 on pathogenic bacteria in vivo and in vitro.The mixture of nanometer zinc oxide and fermented supernatant of Lactobacillus plantarum BLPL03 showed the stronger ability of inhibition toward Salmonella Typhimurium than nanometer zinc oxide alon.In addition,the changes of intestinal flora in mice were analyzed by RT-PCR technology.The mixture of nanometer zinc oxide and fermented supernatant of Lactobacillus plantarum BLPL03 exhibited synergistic antibacterial activity to bacterial pathogens and increase diversity of intestinal microbial flora in mice.Moreover,weaning piglets were feed the mixture to.explore the growth performance and the impact of health.The results showed that the mixture can improve the ADG,reduce F/G,decrease the rate of diarrhea,promote the growth of weaning piglets effectively,and improve their health.The serum biochemical analysis results showed that the mixture could not damage liver of piglets,and promote the growth of piglets.The RT-PCR results showed that lactobacillus genus bifidobacterium occupied the dominant position in the intestines of piglets after feed the mixture.In conclusion,the study found that Lactobacillus plantarum BLPL03 and nanometer zinc oxide can exert probiotic effect on weaning piglet including the improvement the growth performance and health,which provides a great preference for the development and application of feed additives.