Isolation, identification and degradation characteristics of three thick oil degrading bacteria strains

Abstract

In order to find the microbe suited to microbial enhanced oil recovery (MEOR), three bacterial strains DS1, DS2, and DS3 with excellent degrading effect on thick oil were isolated from the thick oil and water reservoir of oil well 51-82# in Erlian Oil Field. The three bacteria were identified as Acinetobacter sp., Enterococcus sp. and Brevibacterium sp. through 16S rDNA sequence similarity search. Viscosity reducing experiment was conducted using thick oil with a viscosity of 1746 mPa·s (50°C) from Erlian Oil Field as the substrate with the three isolated bacterium alone and their consortium. The viscosity reduced 49.1, 46.6, and 49.0 % by DS1, DS2, and DS3, respectively, during 7 days degradation experiment. However, the reduction rate of viscosity reached 57.0 % with the consortium, which was significantly higher than that of single strain. It demonstrated that viscosity reduced effect was better with the consortium of the three isolated bacteria. The consortium can be applied in MEOR. © Springer-Verlag Berlin Heidelberg 2014.