Microbial degradation of petroleum hydrocarbons - in vitro study

Abstract

Pollution of the environment by petroleum products is a global problem, since its extensive exploitation in broad areas. Microorganisms can degrade or transform toxic, petroleum derivates into harmless products with high efficiency. This study aimed to investigate the biodegradation process of petroleum hydrocarbons in contaminated sediment using indigenous and a combination of indigenous and allochthonous microorganisms. The allochthonous microorganisms that were added belonged to the genera Acinetobacter and Citrobacter. The experiment lasted two weeks, and the degradation process took place in a closed vessel on a Micro-Oxymax respirometer. Total petroleum hydrocarbons (TPH) were extracted and determined using a gas chromatograph with a flame ionization detector. The number of microorganisms at the beginning and end of the experiment was also determined. The results on the respirometer and gas chromatography indicated that the microorganisms were metabolically active. Indigenous microorganisms reduce the amount of TPH by 32.0% and the combination of indigenous-allochthonous microorganisms by 33.6%. The results showed that there is no significant difference between the application of autochthonous and the combination of indigenous-allochthonous microorganisms for the reduction of TPH in contaminated sediment, suggesting a high potential of autochthonous microorganisms for bioremediation processes.