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【目的】探讨海洋芽孢杆菌(Bacillus marinus)B-9987菌株的代谢产物BMME-1,对植物病原真菌茄链格孢菌的抑菌作用机理。【方法】分别使用分光光法、气相色谱-质谱GC-MS联用技术、红外光谱法等,检测了BMME-1处理病原真菌后,菌体渗透性、细胞壁及细胞膜成份的变化。【结果】BMME-1对茄链格孢菌的抑菌中浓度(MIC50)为6.2mg/L,最小杀菌浓度(MFC)为50mg/L,在MIC50浓度或高于此浓度处理靶标菌,将导致菌体蛋白质、核酸等大分子物质的外流;处理菌株葡聚糖结构β—型糖苷键、碳—氧键(C—O)、碳—氢键(C—H)等基团的特征吸收强度降低,—OH、CO的伸缩振动吸收强度升高;菌体细胞壁几丁质结构中酰胺I键吸收强度发生变化;与对照菌株的麦角甾醇含量(62.52±3.31%)相比,处理菌株麦角甾醇减少为(56.36±2.52)%,同时出现麦角固醇合成中间产物粪甾醇。【结论】BMME-1对病原真菌的抑制表现为:干扰细胞膜麦角甾醇的合成从而改变了细胞的通透性;对细胞壁葡聚糖结构的影响较大而几丁质次之。
【Objective】 The purpose of this study was to investigate the bacteriostasis mechanism of BMME-1, a metabolite of Bacillus marinus B-9987, against Alternaria solani, a plant pathogenic fungus. 【Method】 The changes of cell permeability, cell wall and cell membrane components after BMME-1 treatment of pathogenic fungi were detected by spectrophotometry, gas chromatography-mass spectrometry (GC-MS) and infrared spectroscopy. 【Result】 The MIC50 of BMME-1 against Alternaria solani was 6.2 mg / L, and the minimum bactericidal concentration (MFC) was 50 mg / L. The target bacteria were treated with MIC50 or above, Resulting in the outflow of macromolecules such as bacterial proteins and nucleic acids. The characteristic absorption of β-glucosidic bonds, C-O and C-H groups in the dextran-treated glucan structure The intensity of absorption of the stretching vibration of -OH and CO increased. The absorption intensity of amide I bond changed in the cell wall chitin structure. Compared with the ergosterol content of the control strain (62.52 ± 3.31%), the processing strain ergot The decrease of sterol was (56.36 ± 2.52)%, at the same time, the production of ergosterol, an intermediate of the ergosterol, was observed. 【Conclusion】 The results showed that the inhibition of pathogenic fungi by BMME-1 was as follows: interfering with the synthesis of ergosterol on cell membrane, thus changing the permeability of cells; the effect of BMME-1 on the structure of dextran was greater than that of chitin.