Isolation And Identification Of Anti-TMV Marine Bacteria And Activity Of The Fermentation Products

The anti-viral activity of marine microorganism was few studied, much less their activity on plant virus. To make good use of the rich marine resourse in Fujian Province, the anti-TMV(Tobacco mosaic virus) strains had been isolated and screened, which will provide some information for the research of microbial pesticide.Marine bacteria were tested for their anti- viral activities angainst Tobacco mosaic virus. Six strains of them showed high activities. Two of them 9a and 10b with strong anti- viral activities were selected for further research.The results showed that both strains had strong activities of passivating TMV particle, the inhibition rates were 95.26%,92.18%respectively. Both of them not only could inhibit the reproduction of TMV particle in vitro, the inhibition rates were 36.1 %,35.1% respectively, but also could inhibit the reproduction of TMV particle in vivo, the inhibition rates were 15.18% ,39.76% respectively .The both strains could induce tobacco produce resistance to TMV by enhancing the activity of defensive enzymes(POD, PPO),and the content of chorophyl by spraying the fermentation products. The two strains could protect the infecting locus( the inhibition rates were 62.14%,62.36%).In addition, two bacteria had prominent bioactivity on several plant pathogenic fungi, such as Botryosphae riadothidea,Colletetrichum orbiculare,Fusarium oxysporum f.sp.,and so on. Growth suppression, increasing branches of their offset and swelling in the middle and/or the top of the hyphae were observed with microscope and scanning election microscope.In order to ascertain their taxonomic position, the traditional bacterial systemic identification method and the molecular identification were performed. Based on the morphological, physiological and biochemical features, the two bacteria were both identified as Bacillus sp. Through the comparative 16SrDNA sequences analysis, the 16SrDNA sequence of 9a had high homologh (99%) with Bacillus cereus , the 16SrDNA sequence of 10b had high homologh (99%) with. Bacillus aquimaris. Therefore 9a was subject to Bacillus cereus and 10b was subject to Bacillus aquimaris.According to the result of screening out the fermentation produces with activity, Bacillus cereus was selected for further study in order to purify the protein with anti-viral activity. The results showed the anti-viral activity could not be extracted from the leavening by organic menstruum. A protein was purified to homogeneity through saturation of ammonium sulfate salting , DEAE Sepharose Fast Flow ion-exchange chromatography and Sephadex G-50 gel-filtration chromatography , which could inhibit the infection of TMV. The MW of the protein was 26KDa determined with SDS-PAGE . The inhibition of the protein to TMV was 80.2% when the concentration was 50μ g/mL.