Evaluation of the Biodegradation of Petroleum Contaminants by Pseudomonas Aeruginosa in the Caspian Sea Coastline Waters

Water plays an essential role in supporting life on earth and sea worldwide, requiringclean, safe, high quality and sustainable resources. Nowadays, many water resources have been contaminatedwith toxic compounds originating from petroleumdue to economical and industrial developments. There is anurgent need to clean up the waters with environmentally friendlyand inexpensive methods. This study investigated the biodegradation of total petroleum hydrocarbons (TPH) using Pseudomonas aeruginosa (P. aeruginosa) in southern Caspian Sea coastline. Coastline sediment samples were collected, with P. aeruginosa being the predominant strain. The bacteria were cultured in triplicates in the presence of 0.5, 1, 2 and 4% of gasoline andunder specific experimental conditions of varying temperature, pH, salinity, shaker speed, and incubation periods. The data representing the gasoline biodegradation in the samples were statistically analyzed.  
At optimized experimental conditions for temperature, pH, salinity, incubation period, and shaker speed, maximum biodegradation of TPH was achieved by culturing P. aeruginosa strains with the sea water samples containing varying concentrations of gasoline. The gram-negative bacteria, P. aeruginosa, almost completely biodegraded TPH contaminants from the samples’ culture media over 28 days of incubation. We conclude that the use of P. aeruginosa is an efficient method for the biodegradation of Caspian coastal waters contaminated with TPH.