Indian Journal of Science and Technology

Abstract

Objective: To isolate potential hydrocarbon degraders from different habitats within the United Arab Emirates (UAE) contaminated with Hydrocarbon Compounds (HC) and assess their degradation potential by a rapid qualitative method. Methods/Analysis: Eight different oil contaminated samples were collected for isolation of Hydrocarbon Degrading Bacteria (HDB) on the surface of nutrient agar plates where the appearance of bacterial colonies was observed and then phenotypically and biochemically characterized. Isolates were screened for HC degradation by the “whole plate diffusion” method after observation of the bacterial growth around the hole. PCR analysis was carried out to detect the key degrading gene, alkane hydroxylase gene (AlkB) in the positive HDB. Findings: Results indicated the recovery of 19 isolates from different HC contaminated samples with nine isolates namely (2A, 1D, So1, S1A, S3, KF1, SO2, AJ1 and 2B) were identified as positive degraders for one or more of the tested hydrocarbon compounds. The majority of these isolates were able to utilize heptane as a sole carbon source for their survival while the isolates SO2, S1A and S3 were the most potent as indicated by their growth around the agar hole-plate. Degradation of hydrocarbon compounds by indigenous microbial communities to marine environment was shown to be successful with a significant biodegradation role can be played by the recovered isolates. PCR analysis of the positive degraders for the presence of AlkB gene showed two groups with different band size products; group 1 (G1) (~330 bp) and group 2 (G2) (multiple of 330 pb). Novelty/Improvements: This study confirmed the HC degradation after detecting the marker AlkB gene in the positive degraders, and the use of th “Hole plate diffusion method” as a rapid qualitative evaluation method for bacterial HC degradation by bacteria.

Keywords: AlkB gene, Degradation, Hydrocarbon, Oil Spills, PCR