生物表面活性剂鼠李糖脂性质的研究

Study on the Properties of Rhamnolipids as Biosurfactants

为探究鼠李糖脂用作生物表面活性剂的潜力,以铜绿假单胞菌1.10452发酵生产的鼠李糖脂为研究对象,利用高效液相色谱-质谱联用法(HPLC-MS)进行成分鉴定,并测定其临界胶束浓度(CMC)、乳化性、起泡性及抗菌活性。成分分析结果表明,该鼠李糖脂主要由9种同系物组成,且以双鼠李糖脂为主要成分。鼠李糖脂的临界胶束浓度为80 mg/L,其表面活性优于十二烷基硫酸钠(SDS)。与对照组相比,鼠李糖脂对大豆油(乳化指数为63.75%,余同)、液体石蜡(65.69%)和正己烷(52.54%)均表现出较好的乳化性。鼠李糖脂的起泡性和泡沫稳定性在纯水中与SDS接近,且在硬水中显著优于SDS。此外,鼠李糖脂在不同温度(-20~121℃)、氯化钠质量浓度(0~25 g/L)及pH值(6~13)条件下均能够保持较好的表面活性和乳化能力。抑菌圈实验结果表明,鼠李糖脂对金黄色葡萄球菌、大肠杆菌、白色念珠菌具有较强的抑菌活性。

The rhamnolipids components that fermented by Pseudomonas aeruginosa 1.10452 were analyzed by high performance liquid chromatography-mass spectrometry(HPLC-MS)in order to explore the potential of rhamnolipids as biosurfactants,and the critical micelle concentration(CMC),emulsifying activity,foam property and antibacterial activity of rhamnolipids were measured.The results of component analysis shows that the rhamnolipids are mainly composed of 9 homologues,and dirhamnolipid is the main component.The critical micelle concentration of rhamnolipids is 80 mg/L and its surface activity is better than that of sodium dodecyl sulfate(SDS).Compared with the control group,rhamnolipids shows excellent emulsifying properties on soybean oil(63.75%),liquid para-ffin(65.69%)and n-hexane(52.54%).The foaming ability and foam stability of rhamnolipids are close to that of SDS in pure water,but significantly better than that of SDS in hard water.Furthermore,rhamnolipids exhibits good surface activity and emulsifying activity at different temperature(-20~121℃),ionic strength(0~25 g/L)and pH(6~13).The results of inhibition zone test show that rhamnolipids has strong inhibition ability to Staphylococcus aureus,Escherichia coli and Candida albicans.