Biodegradation of hydrocarbons and cultivable bacterial diversity in rada tilly coast line, patagonia, Argentina

Rada Tilly city is located between Comodoro Rivadavia and Caleta Olivia cities. Both cities have oil industry activity and oil tankers sail in front of the beach on their way to the loading buoy. The aim of the work was to study the bacterial communities and their capacity to use hydrocarbons. We took samples from three different points in every season of the year, both sediment and seawater samples. Oligotrophic and hydrocarbon degrading bacteria counts were done, and the mineralization of diesel, kerosene, gasoline, oil and lubricant oil were carried out during 50 days. Bacterial communities were grown for 10 days on oligotrophic liquid media and media containing phenanthrene and hexadecane as contaminants and analyzed by methyl fatty acids (FAMEs) profiling. In addition, bacterial isolates obtained were identified by FAMEs. The results showed that the cultivable bacterial communities were similar in spring, summer and autumn and this was made up of Pseudoalteromonas, Rhodobacter, Aeromonas, Ochrobactrum, Photobacterium, Brevundimonas and Vibrio. In winter season, the bacterial communities changed and were made up of Micrococcus, Staphylococcus, Bacillus, Arthrobacter and Paenibacillus. The hydrocarbon mineralization was higher in sediment samples than in seawater samples. The best results were observed in summer. The best values were obtained from oil, diesel oil, kerosene and lubricant oil.