The biodegradation efficiency on diesel oil by two psychrotrophic Antarctic marine bacteria during a two-month-long experiment

Two psychrotrophic bacterial strains isolated from Antarctic seawaters were investigated for their capability to degrade commercial diesel oil. The efficiency of hydrocarbon utilization was studied at 4 and 20 °C over a period of two-months. Strains were cultured in a mineral liquid medium supplemented with diesel oil as the sole source of carbon and energy. The viable counts for the bacterial abundance estimation and the culture extractions for the subsequent gas-chromatographic analysis were carried out simultaneously. The biodegradation efficiency was higher at 20 °C than at 4 °C for both strains and the decrease in hydrocarbon concentrations reached more than 85% after 60 days of incubation at 20 °C. Our results suggest the possible exploitation of these two bacterial strains in future biotechnological processes, directly as field-released micro-organisms both in cold and temperate contaminated marine environments