Isolation And Identification Of Paenibacillus Polymyxa Cp-S316 Strain And Extraction And Purification Of Active Substance Secreted By Paenibacillus Polymyxa Cp-S316 Strain

A bacterium named Paneibacillus polymyxa is screened from soil sample of Mountain Tai. It secrets a large amounts of active substance which can inhibit against several plant and animal diseases,such as Candiada albicans ,Aspergillus flavus Link and Nomuraea rileyi Farlow .The determination show that it is a strain of paenibacillus polymyxa through measuring its G+Cmol% and the sequences of bases of 16SrRNA. The cultural conditions such as temperature, fermentation period and the compound of medium are studied. The result of test show that suitable factors for both bacterium to grow and active substance to produce are 28℃,200rpm and 72 hours. The bacterium is gotten through centrifuge with 8000rpm for 20min.Then the bacteria is diluted and colophony named S-8 is put into and used to absorbed active substance for 4 hours. The active substance is unshiped from colophony through acet. After the acet is vaporized, The active substance in water is gotten. And which is vaporized at low temperature .Then the crude active substance is purified by column chromatography on sephadex G-75.After a series of purifications again ,we could get some white powder at last .Though the active substance is diluted to50μg/ml, The activity is still checkeded-up through Phyto phtnora casicileon.The purified active substance is insensitive to heat, resistant to chloroform,ethanol and the orhers.In addition, the active substance is sensitive to high pH(10~14),but it is not sensitive to low pH(1~5).Furthermre, when the pH is made to low again , The activity of it's comes back.