芽孢杆菌HBS-4产生的表面活性剂及其与原油相互作用研究

菌株HBS-4是从油藏分离的1株芽孢杆菌,该菌株在其代谢过程中产生脂肽和糖脂类生物表面活性物质.可将发酵液的表面张力降低到25.6 mN/m.在细菌与原油相互作用的过程中,生物表面活性剂不仅具有分散、乳化原油的作用,而且有协助细菌代谢原油的作用.实验结果表明,生物表面活性剂在pH值5～12之间保持稳定,当pH值小于5时,会逐渐失活,所以控制发酵液的pH值,有利于细菌对原油的降解.原油与细菌作用12 d后,原油的沥青质和芳烃组分被转化和降解, 相对含量分别降低了2.89%和17.39%,原油的饱和烃∑C21/∑C22 比值由开始的0.39升为1.36, 长链的饱和烃被降解为短链的饱和烃.

Properties and Effect on Crude Oil of Biosurfactant Produced by Bacillus HBS-4

Bacillus, named HBS-4, isolated from oil reservoir is studied. HBS-4 can produce lipopeptide .glycolipid and ether in metabolism. During the interaction between strain HBS-4 and crude oil, biosurfactant can not only disperse and emulsify crude oil but also assist the bacterium to metabolize crude oil. The research results indicate that biosurfactant is stable if the value of pH of the culture broth is kept between 5 and 12, but when the value of pH is below 5, the biosurfactant will lost activity gradually. It will be beneficial for biodegradation to control the pH of the broth. The strain could convert and degrade aromatic hydrocarbons and asphaltenes, and decrease the content of heavy fractions in crude oils. The relative contents of aromatic and asphaltenes decreased 17.39% and 2.89% respectively.