植物精油对大肠杆菌抗性的影响研究
毕业论文关键词：肉桂精油、直接保护、交叉保护、大肠杆菌、抗性
Effect of plant essential oils against Escherichia coli resistance
Abstract:In this study, the antimicrobial effects of cinnanmon essential oil,clove essential oil, ginger essential oil on E. coli are evaluated. And select the best antimicrobial activity of essential oils as a bacteriostatic agent to study the effects of E.coil resistance. The induction of direct protection against cinnamon of cross protection against various stresses (high temperature 45℃；lactic acid, pH 4.5;NaCl 1g/10mL) after exposure to sublethal amounts of cinnamon was also evaluated. The main results are as follows:(1) cinnanmon oil、clove oil and garlie oil all decreased the cell viability of E. coli, cinnamon oil whose MIC is 250μg/mL is the best of them.(2) cinnanmon oil decreased the cell viability of E.coil in LB broth over 120min of exposure at all assayed concenteations (MIC,1/2MIC,1/4MIC).(3) Sublethal concentrations of E.coil in cinnamon oil, the direct protection and cross-protection did not change significantly impact resistant E.coil.(4) In increasing concentrations of continuous adaptive culture experiments, cinnamon oil had no significantly effect on E.coil resistance.
Key words:
Cinnanmon oil; direct protection; cross-protection; E. coli, resistance
目录
1引言 1
1.1 植物精油现状 2
1.1.1 植物精油的种类 2
1.1.2 植物精油的特点 3
1.2植物精油对细菌的抑制效应 4
1.3植物精油的抑菌实验现状 4
1.3.1牛至，迷迭香或大蒜精油的抑菌实验 4
1.3.2含佛手柑精油的壳聚糖的抑菌实验 4
1.3.3牛至或百里香精油的抑菌实验 5
1.3.4丁香、茴香等精油的抑菌实验 5
1.4食品保鲜方法研究进展 5
1.4.1涂膜保鲜 5
1.4.2可食性薄膜保鲜 6
1.5本课题的研究目的和意义 8
2实验材料和方法 9
2.1 实验材料 9
2.1.1植物精油 9
2.1.2菌种和培养基 9
2.1.3试剂 9
2.1.4主要仪器 10
2.2 实验方法 10
2.2.1精油的最低抑菌浓度（MIC）的测定 10
2.2.2动态杀菌曲线 10
2.2.3直接保护效应 10
2.2.4 间接保护效应 11
2.2.5连续的适应性培养 11
3结果与讨论 11
3.1植物精油的筛选 12
3.1.1精油对大肠杆菌的MIC的测定 12
3.1.2动态杀菌曲线 12
3.2直接保护效应 13
3.3间接保护效应 14