产表面活性剂解烃菌的筛选及其降解条件研究

以原油为唯一碳源和能源,从新疆克拉玛依油田土壤中筛选出1株能产生物表面活性剂的高效解烃菌XJBM,经形态观察、生理生化特征和Biolog分析,初步鉴定该菌为铜绿假单胞菌(Pseudomonas Aeruginosa)。薄层色谱分析结果表明,XJBM产糖脂类生物表面活性剂,在最适发酵条件下,生物表面活性剂的产量可达2.25 g/L,可将发酵液表面张力从68.20 m N/m降低到32.50 m N/m,乳化指数(E24)达到81.8%。采用单因素试验对影响XJBM降解率的因素进行了研究,得出最适降解条件为p H 7.5,温度30℃,盐浓度5 g/L,接种量10%。在此条件下,菌株对1%石油烃的7d降解率为63.78%。

SCREENING OF BIOSURFACTANT-PRODUCING BACTERIA FOR DEGRADATION OF PETROLEUM HYDROCARBON AND ITS DEGRADATION CONDITIONS

A biosurfactant-producing strain，named XJBM，was isolated from the oil contaminated soil of Karamay of field in Xinjiang，with crude oil as the sole carbon and energy source via enrichment culture． XJBM was identified as Pseudomonas Aeruginosa based on morphology，physiological and biochemical characteristics and the analysis of Biolog system． Glycolipid was found as the main components of the produced biosrfactant，which was examined by thin-layer chromatography． Under the optimal fermentation conditions，the yield of biosurfactant produced by XJBM could reach 2. 25 g /L． This biosurfactant could reduce the surface tension of culture broth from 68. 20mN/m to 32. 50 mN/m and emulsify paraffin oil to an appreciable level ( E24 = 81. 8%) ． The results of the single factor experiments showed that the optimum degradation conditions for strain XJBM were as follows: initial pH of 7. 5，temperature of 30 ℃，salt concentration of 5 g /L and inoculation amount of 10%． Under that condition，the degradation rate of strain XJBM for oil concentration with 1 g /L was 63. 78% after 7 days at shaking rate of 150 r /min．