Studies on the biodegradation of three groups of pure n-alkanes in the presence of molasses and mineral fertilizer by Pseudomonas aeruginosa

A laboratory biodegradation study of three arbitrary groups of pure n-alkanes chosen according to their carbon chain length was undertaken. The breakdown of n-alkanes was assessed using repirometry and gas chromatography in the presence of Pseudomonas aeruginosa. Molasses or mineral fertilizer were added to the batch culture to investigate their effects on n-alkane biodegradation. The use of molasses enhanced the oxidation rates two fold over a carbon free mineral fertilizer. The percentage reductions for most of the n-alkanes were higher in the presence of molasses than for the mineral fertilizer. For molasses group 1 n-alkanes (C14–C17) and group 2 (C18–C22) were both significantly reduced, whereas in group 3 (C23–C28, and C30) only C23, C24 and C25 showed significant reductions. In the presence of mineral fertilizer only group 2 showed any significant reduction. The significance of using molasses in biodegradation of n-alkanes in relation to oil spills is briefly discussed.