高效破乳菌的破乳效能及活性成分

采用Tween 60、Span 60和航空煤油制备稳定的O/W型乳状液作为模型乳状液，将从大庆油田受石油污染土壤中分离到一株芽孢杆菌属莫海威芽孢杆菌(Bacillus mojavensis)XH-1制成XH-1菌全培养液用于该模型乳状液的破乳，考察培养条件和破乳实验条件对XH-1菌破乳性能的影响。结果表明，与目前现场常用化学破乳剂相比，XH-1菌全培养液具有优良的破乳性能，其对O/W型乳状液破乳24h的破乳率可达85％以上。XH-1菌具有较强的传代稳定性；其最佳培养及破乳条件：以葡萄糖和液体石蜡的混合物为碳源、pH值6. 5、摇床转数140~160 r/min。 XH-1菌的破乳活性成分耐低温不耐高温，超声波破碎处理对其破乳活性影响不大，经胃蛋白酶、胰蛋白酶及尿素处理后其基本失活。显微观察及实验分析表明，XH-1菌主要破乳活性成分为胞外分泌的蛋白物质。

DEMULSIFICATION EFFICIENCY AND THE ACTIVE COMPONENT OF A BACTERIAL STRAIN

A full-culture solution of the strain XH-1 belonging to Bacillus mojavensis isolated from contaminated oily soil in Daqing oilfield was used to demulsify the O/W model emulsion made by Tween 60, Span 60 and kerosene. The effects of cultural and demulsification conditions on the demulsification rate of XH-1were investigated. The results indicated that 85% of demulsification rate was achieved after 24h demulsification of the strain. The demulsification performance of XH-1 was better than those of chemical demulsifiers in the laboratory experiment. The strain XH-1 also showed a stable heredity for biodemulsifier production. The optimal cultural and demulsification conditions were followings: the mixture of glucose and liquid paraffin as carbon source, pH=6.5 and rotating rate of 140-160r/min. The strain did not possess thermostability, but cool-resistance. The ultrasonic treatment of XH-1had little effect on its demulsification performance, however, its demulsification activity was inhibited by the pepsin, trypsin and urea treatments. It is deduced through the microscope observation and analysis that the demulsification active component of the strain XH-1was the extracellular secreted protein substances.