液体接触法与气相接触法对单离香料抗菌作用的影响

Effect of liquid and vapour-phase contact methods on the antibacterial activiy of isolate spices

通过测定单离香料在液体接触、气相接触2种方法对7种供试菌的最小抑菌浓度(MIC值)和最小杀菌浓度(MBC值),用重复测量方差分析、秩和检验探讨不同接触方式对单离香料抗菌效果的影响。结果表明液体接触法中百里香酚、水杨醛对供试菌MIC值均为0.125μL/mL,肉桂醛、柠檬醛MIC值范围为0.25~0.5μL/mL,丁香酚、芳樟醇的MIC值范围为0.25~2.0μL/mL。气相法试验中水杨醛、百里香酚对供试菌的MIC值均为0.125μL/mL,芳樟醇MIC值范围为0.25~1.0μL/mL,肉桂醛、柠檬醛MIC值范围为0.5~1.0μL/mL,而丁香酚在供试范围(8μL/mL)内仅对副溶血性弧菌有抗菌作用。用MIC值重复测量方差分析,水杨醛、百里香酚在液体接触法与气相接触法存在显著性差异,P<0.05,液体接触法明显优于气相法;从MBC值分析,芳樟醇、水杨醛、丁香酚在2种接触方式中存在显著性差异,P<0.05,其中芳樟醇、水杨醛的液体接触法明显优于气相法,而丁香酚则相反。单离香料与菌体的作用方式会影响其抗菌效果,因此利用单离香料的抗菌性能开发新型抗菌剂,需全面评估其抗菌性能。

The aim of this study was to test the antibacterial activity of selected isolate spices against pathogens microorganisms by two types of contact mothods(liquid and vapour-phase contact).The isolate spices were tested against an array of four types of Gram-negative bacteria(Escherichia coli,Salmonella typhimurium,Shigella flexneri,Vibrio parahaemolyticus)and three types of Gram-positive bacteria(Bacillus cereus,Listeria monocytogenes,Staphylococcus aureus).The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of different isolate spices were determined by the broth dilution method in liquid contact method and the disc volatilization method was used in the vapour-phase contact method.The results show that the antimicrobial activity of the six isolate spices in the liquid contact assay are as follows:thymol>salicylaldehyde>cinnamaldehyde>citral>eugenol>linalool.The MIC values of thymol and salicylaldehyde were both 0.125μL/mL.The value of cinnamaldehyde and citral were in the range of 0.25 to 0.5μL/mL,and the value of eugenol and linalool were 0.25-2.0μL/mL.cinnamaldehyde and citral range from 0.25-0.5μL/mL,eugenol for 0.25-2.0μL/mL and linalool for 0.25-2.0μL/mL.In the vapour-phase contact assay,the antimicrobial activity was in the order of thymol and salicylaldehyde>linalool>cinnamaldehyde>citral>eugenol.The MIC values of thymol and salicylaldehyde were both 0.125μL/mL,linalool values ranged from 0.25 to 1.0μL/mL,citral were mostly 0.5-1.0μL/mL and cinnamaldehyde ranged from 0.5 to 1.0μL/mL,while eugenol only effective against V.parahaemolyticus in the test range.According to the analysis of variance of repeated measurement by the MIC values,thymol and salicylaldehyde were significantly difference between the liquid contact method and the vapour-phase contact method,P<0.05,and the liquid contact method was significantly better than the vapour-phase contact method.The analysis of MBC values,linalool and salicylaldehyde had significant differences in the two contact methods,P<0.05,in which the liquid contact method of linalool and salicylaldehyde was significantly better than vapour-phase contact method,while eugenol was the opposite.In conclusion,the different assay methods between isolate spices and pathogens would lead to various antimicrobial effects.Therefore,the development of new antimicrobial agents using the antimicrobial properties of isolate spices requires a comprehensive evaluation of their antibacterial properties.