3株原油降解细菌鉴定及其降解和驱油特性研究

Identification of 3 strains of crude oil degradation bacteria and its characteristics of degradation and oil-displacement

筛选可提高原油采收率的细菌,进而考察其降解、发酵及增油性质。以原油为唯一碳源,采用稀释平板法分离增油菌株;通过观察原油平板上的菌落生长状况、发酵瓶中原油性质变化筛选具有增油潜力的菌株;通过菌落与细胞形态、生理生化特性及16S r DNA序列分析鉴定菌株;利用气相色谱法、柱层析等方法分析菌株对原油化学组成的影响;并采用室内模拟试验研究供试菌株发酵液的驱油效果。结果表明:从分离自原油及油污土壤的17株细菌中筛选出3株有增油潜力的细菌,经鉴定分别为Dietzia cerrcidiphylli(X10)、Micrococcus yunnanensis(X19)及Pseudomonas aeruginosa(X22);3株细菌作用后原油化学成分产生了显著变化,X19对沥青的降解率高达到65.7%,X10对胶质、芳香烃的降解分别达到84.4%、32.15%,烷烃类成分均有不同程度的增加;X22可合成糖脂类表面活性物质;Pseudomonas aeruginosa发酵液在模拟试验中的驱油率较水驱提高了33.5%,且在低渗及非均质模拟介质中驱油效率较高;筛选得到的3株细菌中均有较好的增油潜力,其中Pseudomonas aeruginosa在室内模拟试验中驱油效果较好,适宜于微生物增油技术的研究和应用。

The bacteria for microbial enhanced oil recovery （ MEOR） were screened,and then the characteristics of degrada-tion, fermentation and oil-displacement of the bacteria were investigated in this study. One crude oil as the sole carbon source was used to isolate the crude oil degrading strains by improved dilution-plate method. The bacteria strains with MEOR potential were screened through observing the change of bacteria colony growth in the plates and crude oil properties in fer-mentation flask. Then the strains ＂were identified through the colony and cell morphology, physiological-biochemical tests and 16S rDNA sequence analysis. Also,the influences of strains on the chemical composition of crude oil were analyzed by using the gas chromatography and alumina column chromatography. Meanwhile, the oil displacement efficiency of the fermentation broth after bacteria fermentation was studied using the indoor simulation experiment. It is found that 3 strains with enhanced oil recovery potential of the 17 bacteria strains, which were isolated from the crude oil and oily soil, were screened for the fol-low-up tests,which were identified as Dietzia cerrcidiphylli （X10）,Micrococcus yunnanensis （X19） and Pseudomonas aerug-inosa （ X22） , respectively. The 3 strains of bacteria significantly change the chemical composition of crude oil. The asphalt-ene degradation rate of X19 reaches as high as 65. 7%. The degradation of resin and aromatic hydrocarbon of X10 reaches 84. 4% and 32. 15%, respectively. And the saturated hydrocarbon of X10, X19 and X22 is increased at different levels. It is also found that glycolipid surfactant could be produced by X22. The fer^nentation broth of X22 shows that its oil replace-ment efficiency is 33. 5% higher than water in the indoor simulation experiment, and the oil replacement efficiency is high inthe low,permeability or heterogeneous simulation medium. It is concluded that the 3 strains of bacteria have good potential of oil replacement, especially Pseudomonas aeruginosa with the excellent performance in the indoor simulation experiment, which is good for the study and application of MEOR.