In Vitro Bacterial Inhibiting Effects Of A Paenibacillus Polymyxa Strain,and The Effects Of Its Fermentation Product On Performance Of Broilers

Strain B is a strain of bacteria isolated from the gut of Hainan semi-wild chickens.It was found that the strain had the capacities to resist high temperature?65°C?,simulated gastric juice and simulated bile,and to secrete starch hydrolyzing enzymes,proteolytic enzymes and broad-spectrum antibacterial substances.The Strain B of bacteria was identified as Paenibacillus polymyxa by 16S rDNA sequencing analysis,and named as Paenibacillus polymyxa B?PPB?.In this experiment,the antibacterial effect of the PPB fermentation product?PPBFP?was first tested,and then the effects of the PPBFP on the growth performance of broilers were also conducted.In this experiment,the minimum inhibitory concentration?MIC?and minimum bactericidal concentration?MBC?of the freeze-dried PPBFP against various pathogenic microorganisms was determined.The results showed that the freeze-dried PPBFP inhibited the growth of the pathogenic bacteria,with its MICs or MBCs to E.coli K₁₂D₃₁,E.coli K88,Clostridium perfringens type A?CVCC 2030?,Pseudomonas aeruginosa?ATCC 9027?,Salmonella choleraesuis?CVCC 503?,Salmonella pullorum?CVCC 79301?,Edwardsiella tarda?ATCC 15947?,Aeromonas hydrophila?ATCC 35654?,Staphylococcus aureus?ATCC29213?and Streptococcus agalactiae?ATCC 12386?being<391,<391,781,1563,3125,50000,50000,50000,100000,100000,?g/ml respectively.Broilers were used to study the effects of different doses of Premixes of PPBFP?B Premix?on the growth performance.540 twenty-eight-day-old yellow broilers were randomly divided into 6 treatment groups with 3 replicate pens of 30 birds each,and fed 6experimental diets respectively for 3 weeks.The 6 experimental diets?Maxus,B Premix 0,B Premix 25,B Premix 50,B Premix 100 and B Premix 200?were the basal diet supplemented with Maxus?10%Avilamycin?at 100 g/t,and B Premix at 0,25,50,100 and200 g/t respectively.The results showed that:The feed intake of the five groups?Maxus,B Premix 25,B Premix 50,B Premix 100and B Premix 200?were significantly higher than that of the B Premix 0 group?P<0.05?,with their feed intakes being 3.12%,3.82%,6.13%,7.06%and 6.13%higher.The weight gain of Maxus and B Premix 100 were significantly higher than that of the B Premix 0 group?P<0.05?,with their weight gain being 13.8%and 6.61%;but there were no significant differences in feed/gain ratio among groups.The results indicated that the supplematation of PPBFP could promote broiler growth;it is feasible for the PPBFP to be an aternative to antibiotics used in feed industry.