Isolation, Identification Of A Wax Degrading Strain And Research On Its Biosurfantant

The wax content of oil field well is high,and its molecules usually consist of long alkane chains.This makes serious wax precipitation that usually needs some methods to clear.The common paraffin removal measures include hot water,oil or chemical remover and inhibitor.However,these methods are often expensive and labor consuming.Chemical paraffin inhibitor has some negative influences both on the oil quality and workers health.In addition,clearing wax with hot water often results in block up,while hot oil breaks the oil well.In this study,An alkane-degrading stain was isolated from oil-water mixture of the surface in Qinghai oil well.This strain was isolated and characterized by 16 SrDNA.The system envolution was also made,and its biochemical character and optimal culture conditions were investigated.Then the culture conditions and the wax-degrading conditions were optimized.A highly efficient wax-degrading strain Y7 was acquired by ARTP mutation.Moreover,the biosurfactant produced by Y7 was studied.Wax degradation experiment showed that this strain was able to degrade wax and emulsification phenomenon occurred.Then the biosurfactant produced by this strain was also studied.Results are as following:?1?Biochemical character and 16 SrDNA sequence results show that the strain isolated from soil-water mixture is belonging to Alcanivorax dieselolei: G?and no spore.?2?The optimal culture conditions are:the volume of liquid 60 m L/250 m L,initial pH7.0,temperature 33 ?,150 rpm,culture time 7 d,NaCl 30 g/L,K₂HPO₄ 2 g/L,MgSO₄ 0.4 g/L,albumen powder as nitrogen source,vegetable oil as carbon source,The highest yield reaches3.688×1011/m L,increasing 105 times.?3?The optimal wax-degrading conditions are:the initial concentration of paraffin:20g/L,the initial concentration of glucose:12 g/L,initial pH 8.0,temperature 33 ?,180 rpm,culture time 9 d,NaCl 15 g/L,K₂HPO₄ 3 g/L,Fe SO4 0.05 g/L,MgSO₄ 0.8 g/L,The highest wax falling rate:58.87%.?4?The optimal ARTP mutation conditions are:30 s.A highly efficient wax-degrading strain Y7 was acquired,the wax-degrading rate increases to 89.05 %.?5?Mutation Y7 has stable inheritance,and continunous passage 6 times,every generationall can fall wax,and keep at 80%,better than initial strain 51.49%??6?This strain can produce something like biosurfactant,and the biosurfactant exist the out of cell.Its emulsibility and stability very well,it belongs to anionic lipopenic.