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Polar has a unique geography, climate, and environmental characteristics, creating a the polar microorganisms novelty and diversity, it has important value in scientific research, application development, and use of polar microbial screening to inhibit the activity of plant pathogenic fungi strains and activity metabolites, may become a potential new way to plant disease control. In this study, the foundation for of polar microbial its active product promotion of ecological agriculture and application. Thesis laboratory save polar microbial screening inhibition of plant pathogenic fungi activity strains, and its phylogenetic analysis; screened strains of Pseudomonas sp. P4-11 optimization of fermentation conditions, toxicology tests, greenhouse within the anti-efficiency test as well as the nature of the production of antibacterial substances, separation and purification, and structure identification, antimicrobial mechanism. Knife Fusarium (Fusarium oxysporum) indicator bacteria using plate diffusion method preserved 730 Antarctic bacteria strains and antibacterial activity, a total of 12 has strong antibacterial activity and stable activity strains. 16S rRNA species identification and phylogenetic analysis of the results showed that the seven active strains belong false Alteromonas genus (Pseudoalteromonas), 2 strains belong to the genus psychrophilic (Psychrobacter), 2 strains belong to the genus Pseudomonas (of Pseudomonas) one belonging Lun black ink Escherichia (Rheinheimera). The antibacterial spectrum measurement results show that the inhibitory spectrum of different active strains differ 12 active strains of knife Fusarium fungus, pepper Phytophthora (Phytophthora copsici) large dahliae (Verticillium dahliae) and melon death leather bacteria (Thanatephorus cucumeris) have a certain extent of the Portuguese sticks Rhizopus (Rhizopus stolonifer) no inhibition; among strains Pseudoalteromonas sp. 1-Z11, Pseudoalteromonas sp. 1-Z18 Pseudoalteromonas sp. 4-Z11 Psychrobacter sp. 4-Z18, Pseudoalteromonas sp. IS-010-07-1, Pseudoalteromonas sp. P3-11-10-1 and Pseudoalteromonas sp Z18-3, the remaining five strains of rice sheath blight fungus (Rhizoctonia solani ) have inhibitory effects. Strains of Pseudomonas sp. Inhibitory effect of P4-11 is superior to the other strains, strains studied as a next step. Response Surface Methodology strain of Pseudomonas sp. P4-11 the antibacterial activity fermentation conditions results showed that the optimum fermentation conditions of strain: bran 0.9134% 0.6485%, yeast powder, salinity 1.25 ‰, incubation temperature 13 ° C, the initial The pH value of 8.75, the liquid volume of 80 mL/250 mL, inoculation amount of 1%. Cultured in the medium and fermentation conditions optimized for 120 h, measured inhibition zone diameter of 31.50 mm, 15.60% higher than before (27.25 mm). Strains of Pseudomonas sp. P4-11 the fermentation broth toxicology test results show that the rat acute dermal, acute oral toxicity level for low toxicity and no abnormal guppy. Greenhouse potted control efficiency tests showed that the Pseudomonas sp. P4-11 1:1 dilution of the fermentation broth of cucumber powdery mildew control effect was 68.26%, 66.57% 1:2 dilution control effect, were higher than 1% wuyiencin agent 500-fold dilution of 63.71% control efficiency. Strains of Pseudomonas sp. P4-11 stability characteristics of the active substance research results show that the antibacterial activity of the fermentation broth to save time (0-8 weeks), temperature (30 ° C -60 ° C), pH (6.0-11.0) values ??have good stability, the antibacterial substances produced as a class of medium-polar substances. Detectable antibacterial activity tracking, using ethyl acetate extraction, silica gel column chromatography, high performance liquid chromatography, were isolated and purified strains of Pseudomonas sp. P4-11 in the fermentation broth antibacterial substances, three purity than high possessed significantly inhibitory effect of compound (T2-20-7-11-5, T2-20-7-11-6, T2-20-7-11-7). Using mass spectrometry (MS), NMR (1 ~ H NMR) / C NMR ((13) ~~ C NMR) techniques were used to structure identification. The results show that the compound of T2-20-7-11-5 and T2-20-7-11-7 are the nonylphenol polyoxyethylene ether compound. The scanning electron microscope compound T2-20-7-11-5 knife Fusarium spores ultrastructural changes affect the results found that the compounds can abnormal changes in the morphology of the knife Fusarium spores, spores outer layer vesicles disappear some spore surface local depression, spores between sticking together the cell wall severe deformity enlargement, rupture, spills the contents, and even some of mycelium surface severe deformity enlargement.
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