生物破乳剂产生菌的筛选及破乳效能研究

Isolation and demulsification efficiency of a strain produced from a bio-demulsifier

建立一套高效的生物破乳剂产生菌筛选方法是解决破乳剂产生菌筛选困难的主要途径,利用这种方法从大庆油田采油废水中分离、筛选得到1株对水包油型(O/W)和油包水型(W/O)两种乳状液均具有破乳效能的高效生物破乳剂产生菌,该菌对这两种乳状液在20 h的破乳率均可达90%以上。生理生化鉴定及基于16S rDNA基因序列的系统发育分析表明,该菌属于芽孢杆菌属(Bacillus),菌株编号LH1。实验发现,LH1菌的有效破乳成分为胞外代谢物质,低温、高温及超声破碎处理均对其破乳活性无明显影响,说明破乳菌LH1具有良好的应用价值。

A highly efficient, convenient method was established to isolate strains from bio-demulsi- tiers. One strain, named as LH1, with a high and steady demulsification activity, was isolated from pe- troleum-contaminated waste water in Daqing oilfield. The cell culture could demulsify more than 90% of the O/W or W/O emulsions within 20 h. The physiological-biochemical characterization and phylogenetic analysis based on the 16S rDNA gene sequence show that the strain LH1 belongs to the genus Bacillus. It was deduced that the effective component for demulsitication of the strain LH1 was the extracellular me- tabolite. Autoclave sterilization, freeze-thaw process, and uhrasonication do not affect on its demulsifica- tion performance. Thus, our experimental results indicate that the strain LH1 has a high demulsification efficiency with a good application potential.