Isolation Of Microbes For Bacteria Agent Recovering Oil And Metabolic Behavior Of Isolates Under Different Environment

Microbial enhanced oil recovery (MEOR) is an important tertiary recovery technologyutilizing microorganism beneficial activity and metabolite. The key step of MEOR isselecting an excellent bacterium for oil recovery.In this study, eleven bacteria strains were isolated from the microbial agent for MEORand crude oil. The isolates’ characteristics on physiology and biochemistry proved that strainsY-1and Y-5were Bacillus, Y-2and Y-6were Arthrobacter, Y-3was Corynebacterium, Y-4,J-1, J-2, J-4, J-5and J-6were Acinetobacter.Based on emulsifying effect on crude oil of fermentation broth, J-1, J-6, Y-2, Y-5andY-6strains were selected for further fermentation course analysis. With the growth of selectedstrains, the surface tension of fermentation broth reduced rapidly. The experiment resultsdemonstrated that the selected strains could produce biosurfactant.The analysis results by silica gel thin layer chromatography indicated that thebiosurfactant produced by selected strains was rhamnolipid.Selected strains could grow at50℃, produced biosurfactant. The fermentation broth ofselected strains could stimulate indigenous microbe of crude oil, emulsified crude oil. Thebinary and ternary mixed fermentation of strains Y-2, Y-5and Y-6showed that fermentationperiod of mixed strains was extended compared with single strain. Mixed strains couldproduce biosurfactant and organic acid, but not gas with hydrocarbon and crude oil. Theactivity of emulsifying crude oil of fermentation broth of mixed strains increased comparedwith single strain.