高效产表面活性剂菌株（Lz2～1）的筛选及其特性研究

从24份含油土壤和水等样品中，经富集培养、摇瓶培养和排油活性测定等方法筛选出一株能以原油为碳源产生表面活性剂的菌株Lz2—1；该菌株可以将水的表面张力由72mN／m降到28mN／m，且发酵液具有较好的乳化活性；经生理生化16SrDNA及生理生化实验确定该菌株为铜绿假单胞菌；提取其代谢产物经薄层层析及红外色谱分析显示，主要的表面活性剂类物质为鼠李糖脂类，其临界胶束质量浓度为0．63047g／L。结果表明，表面活性物质是Lz2—1菌株在微生物采油过程中发挥作用的主要因素。

Isolation and Characterization of Effective Biosurfactant-Producing Bacteria Lz2-1

A strain Lz2--1 capable of crude oil as main source and energy of producing biosurfactants could be isolated by a series of steps including hydrocarbon enrichment culture and shaking culture and oil displacement activity assay etc. The strain was isolated with the best surface activity in 24 samples from petroleum--contained soil, sludge, waste water etc,and identified as pseudomonas aeruginosa by analysis of 16S rDNA gene and physiochemical methods. The strain produced crude biosurfactant has excellent emulsification property and makes the surface tension of water decrease from 72 mN/m to 28 mN/ m. The key components of the crude biosurfactant were extracted and identified as rhamnolipid species by using TLC and FT-- IR analyses. The critical micelle concentration of the biosurfactants is 0. 630 47 g/L. The present study states that the biosurfactants are major factors of Lz2--1 strain in microbial enhanced oil recovery.