【作者】 史德芳；

【导师】 杨洋；

【作者基本信息】 广西大学 ， 制糖工程， 2006， 硕士

【摘要】 本文对仙人掌提取物的分离及抑菌性能进行研究，包括抑菌谱及最低抑菌浓度的确定，通过比较不同提取溶剂对抑菌活性的差异，筛选出最佳的提取剂，探讨了提取物的稳定性，优化了抑菌活性物质的提取工艺，并进一步对抑菌活性物质进行分离，最后对仙人掌提取物影响微生物正常代谢的作用机理进行了研究，结果如下： 1．试验确定了仙人掌提取物的抑菌谱，证明仙人掌醇提取物对细菌有良好的抑制作用，霉菌次之，酵母菌最弱，特别是对大肠杆菌、金黄色葡萄球菌的抑制作用最显著，其最低抑菌浓度均低达6.25％。以大肠杆菌、根霉和酵母菌为指示菌，研究了仙人掌提取物的稳定性。结果表明，提取物的抑菌活性具有较好的热稳定性，对紫外光照射稳定，在中性和酸性条件下的抑菌效果较佳。 2．不同溶剂的提取物的对同一种菌的抑制作用差别较大，其中以甲醇和70％乙醇最好，实验结果依次排序为：甲醇＞70％乙醇＞乙酸乙酯＞正己烷。在相同的时间内，提取液的浓度越高，抑菌率越高；相同浓度的提取液，作用时间越长，抑菌率也越高。 3．不同预处理方式对仙人掌提取物抑菌活性有一定的影响，以仙人掌更多还原

【Abstract】 In this paper ,extracts from opuntia was tested for its antimicrobial activities, including investigation of its antimicrobial spectrum ,MIC value,The feasible solvent with strongest activities was selected after comparing the differences of antimicrobial activities of different extracts from opuntia with different solvents by measuring their antimicrobial activities. The processing conditions of leaching active substances from opuntia were optimized. The sensitivity to universal factors of the extracts was studied and two active substances were extracted form opuntia and purified by silica gel column and SephadexG-75 gel chromatography. Eventually, it was invstigated that the metabolic mechanism of the experimented microbes affected by extracts from opuntia.1 .The extraction of antimicrobial compound from opuntia and the antimicrobial activities related to temperature、 ultraviolet radiation、 pH and their mutual influence to the extracts was investigated. The result showed that the extracts from opuntia had obvious antimicrobial activities especially to Escherichia coli and Staphylococcus aureus with the minimal inhibition concentration (MIC) : 6.25%.The middle is several mildews, the most weak is Saccharomyces cerevisiae.The extracts from opuntia was stable to temperature、 ultraviolet radiation, antimicrobial activities were better when PH≤7.2.The antimicrobial activities of extraction by different solvents was quite different,methanol and 70%ethanol gave the best result followed by ethyl acetate > normal hexane. In the same action time, the higher the concentration of extraction ,the higher of the inhibition rate is. With the same concentration of extraction, the longer the action time will更多还原