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Studies on the Isolation and Bioactivity of Lipopeptides from the Strain Bacillus Marinus B-9987

Author: LiuRongFeng
Tutor: LiYuanGuang；ZhangDaoJing
School: East China University of Science and Technology
Course: Marine biology
Keywords: Marine Bacillus Lipopeptide Antibacterial activity Separation and purification Structural identification
CLC: Q936
Type: Master's thesis
Year: 2011
Downloads: 97
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Abstract

Marine Bacillus plant Suaeda salsa rhizosphere isolated from the Bohai intertidal zone B-9987, microorganisms in a variety of plants of the Fusarium oxysporum cabbage soft rot bacteria and tomato bacterial wilt pathogen has a strong inhibitory effect, and B-9987 live bacteria living biocontrol agents, microbial pesticides in field efficacy trials Phytophthora capsici, Fusarium disease, anthrax watermelon and tomato bacterial wilt and other plant diseases showed better control effect. , However, has not been isolated from the fermentation broth of the B-9987 antibacterial substances and good stability. In this paper, the separation of the antibacterial activity tracking, isolated from the fermentation broth of the B-9987, the new structure of the series lipopeptide antibacterial compounds and its biological activity, not only shows the new structure of the antibacterial substance created in the agricultural antibiotics potential applications in pharmaceutical and biological surface active agent, and to clarify the microbial pesticides to control plant disease mechanism of anti-bacteria living in B-9987 and laid the material foundation. Use of organic solvent extraction and acid precipitation, the silica gel column chromatography, Sephadex LH-20 column chromatography and HPLC separation techniques such as indicator bacteria, plant pathogenic fungi eggplant cross tenuis tracking isolated from the fermentation broth of the B-9987 8 Antibacterial compounds (collectively, BM). LC-MS and MS / MS results showed that their molecular weights were 1014,1028,1042,1056,1056,1070,1070 and 1084. Combined with NMR, MS and MS / MS techniques identified in which the content larger BM-3 (1042), BM-2 (1056) and BM-1 (1056) and other three compounds were cyclo (D-Pro- L-Gln-L-Asn-L-Ser-D-Asn1-D-Tyr-D-Asn2-D-β-aminotetradecanoic acid) cyclo (D-Pro-L-Gln-L-Asn-L-Ser-D -Asn1-D-Tyr-D-Asn2-D-β-aminoanteisopentadecanoic acid) and cyclo (D-Pro-L-Gln-L-Asn-L-Ser-D-ASN1-the D-Tyr-the D-ASN2-D -β-aminoisopentadecano-ic acid), are the new structure lipopeptide compounds. The physical and chemical properties of the BM, quantitative measurement methods and explore other aspects of the separation process, preliminary findings showed that the heat and acid stability and secondary acidification precipitation combined with macroporous resin adsorption BM purity has been increased to 33.6%. Preliminary Pharmacodynamic studies have shown that BM agricultural antibacterial activity. Tablet antagonistic activity assay results show the BM Bacteriostasis wide spectrum of Botrytis cinerea fungus, of S. rolfsii Atractylodes and melon anthracnose monocytogenes plant pathogens MICs in 25 ~ 200μg/mL; pot experiment results show of 125μg/mL BM on cucumber the control fungicide pyrimethanil gray mold control efficiency of 95.6%, significantly better than the same concentration, 40% pyrimethanil amine carbendazim and iprodione; preliminary results of field efficacy trials of 500μg/mL BM on sesame gray mold relative disease and cabbage downy mildew disease control efficiency of 45.8% and 39.3%, respectively. BM medical activity results demonstrated that BM-1 and BM-3 on Candida albicans yeast MICs 25-50μg/mL ,10-5 mol / L BM-1 in human leukemia cell line HL-60 inhibition 83.8%; B-9987 fermentation supernatant is the surface tension of 26.9 mN / m, indicating that there surfactant preferred compounds.

Studies on the Isolation and Bioactivity of Lipopeptides from the Strain Bacillus Marinus B-9987

Abstract

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