摘要
对不同质量浓度的单癸月桂酸甘油酯的抑菌活性及其抑菌机理进行研究。采用滤纸片法对单癸月桂酸甘油酯进行细菌敏感性测试;二倍试管稀释法测定最低抑菌质量浓度(MIC);光电比浊法测定抑菌效果;二乙酸荧光素(FDA)染色实验研究其对细菌膜通透性的影响;分光光度法测定细菌胞内蛋白含量、细菌细胞壁脂多糖(LPS)含量、细菌菌悬液离心后上清液中核酸物质含量;原子吸收光谱法测定细菌菌悬液离心后上清液中胞内内容物K+、Ca2+、Mg2+含量;扫描电镜观测细菌表面形态变化。结果表明:单癸月桂酸甘油酯对革兰氏阳性菌及阴性菌均有较好的抑制效果,对金黄色葡萄球菌(G+)、枯草芽孢杆菌(G+)的抑制作用主要是破坏其细胞膜及细胞壁,对大肠杆菌(G―)的抑制作用主要是引起细胞壁外膜LPS外泄。
The objective of this study is to explore the antimicrobial activity and mechanism of monoglycerides containing monolaurin and monocaprin. Paper disc method was used to evaluate bacterial susceptibility of monolaurin and monocaprin. Two-fold dilution method was used to test minimum inhibitory concentration （MIC）, and photoelectricity turbidimetry method was used to determine antibacterial efficacy. Orescein diacetate （FDA） was used as fluorescent indicator to reflect the membrane permeability of tested bacteria after treatment with monolaurin and monocaprin. Spectropbotometric method was used to test the leakage of internal substances of tested bacteria, such as protein, nucleic acid, lipopolysaccharide, K＋, Ca2＋ and Mg2＋. The change of cell surface was characterized using scanning electron microscope. Results showed that gram-positive and gram-positive bacteria were susceptive to monolaurin and monocaprin. The activities of monolaurin and monocaprin against Bacillus subtilis （G＋） and Staphylococus aureus （G＋） resulted from the destruction of cell wall and membrane caused by monolaurin and monocaprin. On the contrary, its antibacterial activity against Escherichia coil （G-） resulted from the leakage of lipopolysaccharide in cell walls.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2013年第3期70-74,共5页
Food Science
基金
江西省国际科技合作项目(2010EHB02500)
国家中小企业创新基金项目(11C26213604985)
国家国际科技合作专项(2011DFA32770)
江西省自然科学基金项目(20114BAB204018)
关键词
单癸月桂酸甘油酯
抑菌作用
抑菌机理
monolaurin and monocaprin
antibacterial activity antibacterial mechanism
