壳聚糖及其衍生物对镰孢菌的抑菌机理

Antibacterial Mechanism of Chitosan and Its Derivatives on Fusarium concentricum

本文主要研究3种壳聚糖及其衍生物对绿芦笋病原菌镰孢菌的抑菌活性及抑菌机理。通过测定最小抑菌浓度(MIC)、最小杀菌浓度(MFC)、菌丝生长抑制和孢子萌发抑制实验测定羧甲基壳聚糖(CMC)、水溶性壳聚糖(WSC)和酸溶性壳聚糖(ASC)对镰孢菌的抑菌效果。选取抑菌效果最好的WSC进行抑菌机理研究。通过测定电导率、几丁质酶活性和超微型态分析抑菌机理。结果表明:壳聚糖对镰孢菌生长的抑菌能力由强到弱依次是WSC>ASC>CMC。抑制机理是:WSC通过增加细胞膜的通透性,诱导镰孢菌细胞壁中几丁质的酶活,改变细胞内部结构,使细胞内物质渗漏出胞外,从而达到抑菌的效果。

We research the antibacterial activity and antibacterial mechanism of chitosan and its derivatives on the green asparagus pathogen Fusarium. The fungicidal activity of Carboxymethyl chitosan（CMC）, water-soluble chitosan（WSC） and the acid-soluble chitosan（ASC） were further investigated by determination of the minimum inhibitory concentration（MIC）, minimum fungicidal concentration（MFC）, inhibition of mycelial growth and spore germination inhibition experiments. Select the chitosan that had best inhibitory effect to study the antibacterial mechanism. The antibacterial mechanism were analyzed mainly through conductivity, chitinase activity and determination of micro patterns. Results demonstrated that antibacterial activity of chitosan on Fusarium growth from strong to weak were WSC, ASC, CMC. The antibacterial mechanism study found that WSC by increasing the permeability of cell membranes, cell walls of Fusariuminduced chitinase enzymatic activity, changes in the internal structure of the cell and leakage of intracellular extracellular substances to achieve the effect of inhibition.