Investigation of Bacillus licheniformis OT9 isolated from the Tabriz refinery soil in microbial enhanced oil recovery

Crude oil is the most important energy source in most of the industrial countries. Microbial enhanced oil recovery (MEOR) is a cost-effective method that uses microorganisms or their metabolites to extract the residual oil. The aim of this study is an investigation of effective bacteria in MEOR. In this research, oil contaminated soil and water samples were gathered from Tabriz refinery and the effective bacteria were separated. Identification of selected isolates was performed by sequencing of the 16SrRNA gene. MEOR efficiency of these bacteria was studied using the syringe method. Investigations were done in 1, 2, 4, 7 and 14 days of heating times with different amounts of bacterial inoculation (0.1, 0.2, 0.5 and 1 mL) at a temperature of . To measure the oil recovery factor, 3ml of 5% brine was injected and an adequate time was given to the system until the oil was extracted. Finally, recovered oil value was calculated from the results. Among all microbial isolates, Bacillus licheniformis OT9 was characterized based on molecular and biochemical methods and its performance in MEOR was investigated. The highest recovery factor was attained in the heating time case of 24 and 48 hours, due to accessibility of nutrients for the bacterium and the highest values of inoculation were 0.5 and 1 ml, since the number of bacteria and produced metabolite value were higher and so the effectiveness was better. The highest recovery factor was 89.66 %, for to the injection value of 1 ml and heating time of 48 hours.

کلیدواژه ها:

Microbial enhanced oil recovery ، Bacillus licheniformis ، Soil ، Oil contamination