摘要
本研究以野棉花叶为原料,采用正己烷（料液比1∶20 g/m L）脱脂处理后,以甲醇（料液比1∶25 g/m L）为提取剂提取,经大孔吸附树脂Diaion HP-20层析柱,以抗酵母菌活性为筛选方法获得100%甲醇洗脱液为抗菌活性组分。通过牛津杯法和微量稀释法测定野棉花叶活性组分对供试菌株的抑菌活性、最小抑菌浓度和最低杀菌浓度,采用杀菌曲线和透射电镜初步探究其对酵母菌生长的影响。结果表明,野棉花叶活性组分的浓度为10 mg/m L时,对黑曲霉和酿酒酵母均具有抑制效果,抑菌圈直径分别为：黑曲霉9.20 mm,酿酒酵母15.10 mm。但对不同种酿酒酵母的抑菌活性有所不同,抑菌圈直径范围为14-17 mm,所测得的最小抑菌浓度为29.30-58.60μg/m L,最低杀菌浓度为117.20-468.80μg/m L。杀菌曲线结果表明,活性组分的抑菌作用主要表现在酵母菌的生长对数期;透射电镜观察的结果表明其通过破坏酵母菌细胞壁或细胞膜的结构,导致酵母菌内容物外泄使得细胞死亡。
In the present study,the leaves of Urena lobata L.were used as raw material.U.lobata leaves were treated with n-hexane（ 1∶20 g / m L） to remove the low polarity components,and then extracted with methanol（ 1∶25 g / m L）.By bioassay guide of anti- yeast activity,the 100% methanol elution was obtained as the main active fraction from the crude extract through macroporous resin Diaion HP-20 column chromatography.The antimicrobial activity of all strains was investigated by Oxford cup method. The micro- dilution method was used to calculate Minimum inhibitory concentrations（ MICs） and Minimum fungicidal concentration（ MFCs）.Meanwhile,the effects of the active fraction on yeast growth cycle and cell morphology were observed according to killing curves and transmission electron microscope（ TEM）,respectively.At a concentration of 10 mg / m L,the active fraction exhibited 9.20 mm of inhibitory zone diameter against Aspergillus niger and 15.10 mm of inhibitory zone diameter against Saccharomyces cerevisiae. However,the anti- yeast activity was different from different kind of Saccharomyces cerevisiae with inhibitory zone diameters ranging from 14 to 17 mm.The MICs and MFCs of the active fraction were detected to be in ranges of 29.30-58.60 μg / m L and 117.20-468.80 μg / m L,respectively.The killing curves indicated that the anti- yeast activity mainly occured at the log phase.The TEM results showed that the active fraction killed yeast cells through destructing yeast cell wall and membrane,and resulting in the leakage of cytoplasm.
出处
《食品工业科技》
CAS
CSCD
北大核心
2015年第19期107-111,共5页
Science and Technology of Food Industry
基金
新世纪优秀人才支持计划(NCET-10-0591)
四川省青年基金(2012JQ0019)
关键词
野棉花叶
抗酵母菌活性
杀菌曲线
透射电镜
Urena lobata L.
anti-yeast
killing curves
transmission electron microscope
