Study On Metabolism Of Microbe For Oil Recovery

Microbial enhanced oil recovery, which based on microorganism beneficial activity andmetabolite, has got many advantages such as low cost, easy operation, no damage to geologicstrata and environment amicablity and so on.In this study, various strains effects on oil liquification and emulsification were tested.HB29performed best among these strains, which could make the crude oil emulsified intoparticles in different size and dispersed in culture medium.Biosurfactant played an important role in microbial enhanced oil recovery for theemulsification, reducing viscosity on petroleum and decreasing interfacial tension of oil-water.In this paper, the biosurfactant produced by HB29was analyzed by using TLC and IR. HB29could produced glycolipid surfactant using petroleum or liquid-paraffin as carbon source,glycolipid yield were0.295g/L and0.219g/L.Using liquid-paraffin as carbon source, the effects of different conditions on glycolipidproduction were studied. The glycolipid yield was higher under the conditions of4%ammonium sulfate in medium at initial pH8.0,2%inoculum and liquid volume75mL/250mL.When sodium chloride concentration was below1%in fermentation medium, glycolipidproduction was not affected by sodium chloride concentration. But glycolipid productionwould decrease when sodium chloride concentration was above1%. The addition ofTween-80(2g/L) would increase glycolipid yield6.64%higher than that of control. Whenpenicillin (200mg/L) and streptomycin (100mg/L) were added into fermentation medium at24h after inoculation respectively, glycolipid yield increased14.34%and5.73%higher thanthat of control.By acid-producing tube and pH meter, gas and acid produced metabolitcally by HB29were determined. The experiment results demonstrated that the production rate of acid inliquid-paraffin medium was faster than that in crude petroleum medium, the capacities of gasproduction were different for different carbon sources.Dehydrogenase activity can reflect cell activity and utilization ability for crude oil.Triphenyltetrazolium chloride (TTC) method was used to determine dehydrogenase activity of HB29in crude culture medium. Analysis results showed that there was an intimate relationbetween dehydrogenase activity and the petroleum biodegradation rate of HB29, highdehydrogenase activity was benifit for microbe to utilize oil.