产生物表面活性剂石油降解菌筛选及特性研究

Screening and characterization analysis of oil degrading bacteria producing biosurfactant

目的获得产高效生物表面活性剂的菌株,并判定表面活性剂的结构及探索其特性。方法通过从富油土壤中采用富集培养、血平板分离、排油活性等方法筛选高产表面活性剂菌株并鉴定;采用萃取和柱层析法提纯后HPLC-MS法分析产物结构并分析其理化性质。结果筛选出产生物表面活性剂高效菌BD-5,经鉴定为铜绿假单胞菌;所产生物表面活性剂为8种鼠李糖脂同系物的混合物;鼠李糖脂溶液对液体石蜡、柴油和甲苯都具有较强的乳化能力;当鼠李糖脂浓度高于临界胶束浓度(CMC)时,长链烷烃和多环芳烃在水相中的表观溶解度随鼠李糖脂浓度的增大而增大,摩尔增溶比(MSR)的变化关系为正十六烷>萘>菲>芘。结论 BD-5菌株产生的生物表面活性剂活性突出,有良好的应用前景。

Aim To get one strain of bacterium producing high effecient biosurfactant and decern the structure an characteristics of biosurfactant. Methods The high bacteria surfactant of BD-5 in oily soil is determined throug twice selection from some processes of enrichment culture, blood plate separation and surface tension test. Simulta neously, on the basis of purification by extraction and column chromatography, the structure as well as physical an chemical properties of biosurfactant must be determined using HPLC-MS. Results The selected high bacteria sm factant of BD-5 from oily soil is termed as pseudomonas aeruginosa; on the basis of HPLC-MS test, the high bact~ ria surfactant of BD-5 is examined as the mixture of 8 kinds of rhamnolipid homologues ; it is found that the rhamnolipid solution has strong emulsion effect on liquid paraffin, diesel and toluene. The variation of the molar solubiliz~ tion ratio is thexadecane 〉 naphthalene 〉 phenanthrene 〉 pyrene. Conclusion The above results showed that th BD-5 strain has a greater potential for Soil bioremediation.