Isolation and characterization of Pseudomonas sp NAF1 and its application in biodegradation of crude oil

Production water collected from the "Nafoora" oil water pit, located near the Gallo Oasis, Libya, was used for the screening of obligate hydrocarbonoclastic bacteria that can degrade crude oil. Bacterial strain NAF1 was isolated and characterized after enrichment on crude oil at pH 7 and 30 degrees C. Solid Waste Dates (SWD) and Corn Steep Liquor (CSL) were usedas to enhance biodegradation of crude oil. Strain NAF1 was able to utilize a number of aliphatic and aromatic hydrocarbons. During growth on natural products, high emulsifying activity in the presence of cells was also observed, which indicated the production of biosurfactant by strain NAF1. The new isolated strain NAF1 produced a yellow-green pigment. The bacterial strain showed removal efficiency of 91 and 97 % of crude oil in 28 days when cultivated with >0.5 % (w/v) of pre-treated CSL and SWD, respectively. Alignment of the 16S rRNA gene sequences of NAF1 with sequences obtained by Basic local Alignment search tool (BLAST) search revealed 98 % similarity to P. aeruginosa PAO1. Therefore, the crude oil-metabolizing bacterium could secrete surfactants using agro-industrial products as substrates, which further enhanced hydrocarbon degradation.