Application Fundamental Research On Microbial Degradation For Thick Oil Resources

Using of a set of feasible bacterial screening method, three auxoheterotroph were screened from different sources in the thesis. Two of them are bacillus and gram positive, and the other one is uncertain. All of the three strains are facultative aerobe, and able to tolerant 11.53%(W/V) of NaCl and 85.3℃. They are adapt to the harsh environment of oil deposit.These strains, which can regard thick oil as the only carbon source and grow, will economize the cost. They can produce bio-surfactant, and make the surface tension of the medium decline by 39.60%-44.46%. Bio-surfactant, which can be emulsified crude oil and benefit to exploit thick oil, can reduce the boundary tension of the oil-water and form the steady oil-water emulsion.These strains, which are able to produce acid, can make crude oil pH reducing by 0.54-0.98 units. Acid can dissolve in crude oil, reduce viscidity, reduce interface tension of oil-rock-water, and benefit to exploit thick oil.Soil contains abundant micro-organism. T-strain which does not come from oil source can make the same effect as O-strain and N-strain which come from the domestic oil source.It proved, these screened strains are all facultative aerobe, and tolerant of high temperature and salt-tolerant. They can regard thick oil as the only carbon source to grow, then produce acid and bio-surfactant in a large amount. All these compounds produced by bacteria can be emulsified crude oil. These results demonstrate that the specific purpose project strain can also be screened from not only in oil source.