Changes in the bacterial community composition due to petroleum oil exposure and bioremediation

Abstract EN

The main goal of this study was to monitor the changes of marine bacterial communities due to different trends of oil exposures and after different bioremediation treatments in marine microcosms.

Also to find the relationship between bacterial diversity and biodegradation potentials under different conditions.

The best adaptation conditions to enhance Suez Gulf microflora (SGM) was examined.

Nontraditional methods such as using immobilizing agents and special adapted inocula for bioremediation enhancement were tested.

The changes in bacterial community composition were detected by analyzing the PCR amplified product of 16S rDNA via denaturing gradient gel electrophoresis (DGGE).

DGGE profiles revealed remarkable changes in bacterial diversity due to changing the concentration of oil spell and the mode of exposure.

Gradual exposure to oil was found to enhance the biodegradation potentials of SGM.

Enhanced biodegradation by SGM in the presence of different immobilizing agents in marine microcosms polluted with 5000 ppm base oil revealed remarkable changes in bacterial diversity and enhanced the biodegradation potentials of SGM.

On the other hand, application of biostimulation using inorganic fertilizer and bioaugmentation using different adapted biodegrading inocula revealed severe changes in the bacterial community composition.

The biodegradation potentials of the adapted inoculum AB was as high as twice as that of the other adapted inocula.

It was observable that AB structural fingerprints predominate when added to the oil polluted marine microcosms containing SGM.

In order to achieve successful bioaugmentation results, gradual adaptation protocols are recommended to be applied on the natural consortia.