接触辉光放电等离子体对Fusarium solani的杀菌作用机制及动力学模型研究

Sterilization Mechanism and Kinetic Modeling of Contact Glow Discharge Plasma on Fusarium solani

为研究接触辉光放电等离子体(CGDP)对茄病镰刀菌(Fusarium solani)的杀菌作用及机制,本试验以Fusarium solani为试材,考察CGDP处理过程中电压、处理时间、抗坏血酸浓度、孢子初始浓度等因素对杀菌效果的影响;并对Fusarium solani生长、孢子形态、细胞膜完整性及过程中所产生的活性粒子进行分析。通过Linear、Weibull和Log-Logistic 3种数学模型分析不同电压下CGDP杀菌动力学特性,以相关系数(R^(2))、精确因子(Af)、偏差因子(Bf)和均方根方差(RMSE)4个参数评价拟合效果。结果表明,CGDP对Fusarium solani孢子有着明显的杀菌效果;升高电压、延长处理时间、降低抗坏血酸浓度和孢子初始浓度均能有效抑制孢子生长,使杀菌效率提高(P<0.05);CGDP处理30 min,活性物质(·OH、H_(2)O_(2)、NO_(3)^(-))浓度分别增加至1.57 mg·L^(-1)、73.89 mmol·L^(-1)和12.72 mg·L^(-1),pH值由7.07降至4.66;孢内核酸和蛋白质的渗漏量以及PI染色和扫描电镜结果表明,CGDP对Fusarium solani的杀菌作用可能是通过破坏孢子形态和细胞膜完整性后被活性物质攻击而引起的;模型拟合结果表明,Weibull模型拟合度最高(R^(2)=0.9242),并且RMSE较小(0.6367),可以用于描述和预测CGDP对Fusarium solani的杀菌动力学特征。本研究结果为低温等离子体杀菌技术和杀菌机制研究提供了理论指导。

In order to investigate the sterilization effects and mechanism of contact glow discharge plasma(CGDP)on Fusarium solani,the influences of voltage,processing time,ascorbic acid concentration and initial concentration of spores on the sterilization effects during CGDP treatment was studied,in which Fusarium solani was used as the test material.The growth of Fusarium solani,spore morphology,cell membrane integrity and the active particles produced during the process were also analyzed.In addition,the sterilization kinetic characteristics of CGDP at different voltages were analyzed by three mathematical models,Linear,Weibull and Log-Logistic,and their fitting effects were evaluated by four parameters:correlation coefficient(R^(2)),exact factor(Af),deviation factor(Bf)and root mean square variance(RMSE).The results showed that CGDP had a significant sterilization effect on Fusarium solani spores.Increasing the voltage,extended processing time,decreasing the ascorbic acid concentration and the initial concentration of spores could effectively inhibit spore growth and increase the sterilization efficiency(P<0.05).The concentration of active substances·OH,H_(2)O_(2) and NO3−increased to 1.57 mg·L^(-1),73.89 mmol·L^(-1) and 12.72 mg·L^(-1) after glow discharge for 30 min,respectively,and the pH value reduced from 7.07 to 4.66.The amount of nucleic acid and protein leakage within the spores,as well as PI staining and SEM results indicated that the fungicidal effects of CGDP on Fusarium solani may be induced by attack from active substances affer disrupting spore morphology and cell membrane integrity.The results of the fit showed that that the Weibull model had the best fit(R^(2)=0.9242)and the minimum value of RMSE(0.6367)when describe and predict the sterilization kinetics of CGDP on Fusarium solani.The results of this study should provide theoretical guidance for the study of low temperature plasma sterilisation technology and mechanisms.