Formation of carboxylic acids during aerobic biodegradation of crude oil and evidence of microbial oxidation of hopanes

Watson, J. S.; Jones, D. M.; Swannell, R. P. J. and van Duin, A. C. T. (2002). Formation of carboxylic acids during aerobic biodegradation of crude oil and evidence of microbial oxidation of hopanes. Organic Geochemistry, 33(10) pp. 1153–1169.

DOI: https://doi.org/10.1016/S0146-6380(02)00086-4

Abstract

During the biodegradation of crude oil in the laboratory, significant amounts of carboxylic acids were produced. Medium molecular weight (C10–C20) carboxylic acids were rapidly produced, which coincided with the removal of the n-alkanes but these acids were then also rapidly biodegraded. After extensive biodegradation of the hydrocarbons there was an increase in the concentration of higher (>C20) molecular weight branched and cyclic carboxylic acids which appeared as an unresolved complex mixture (UCM) in the gas chromatograms of these acid fractions. These latter acids appeared recalcitrant to further biodegradation during the experiment. The presence of hopanoic acids with the 17α(H),21β(H) configuration in the most degraded laboratory samples, indicated that biodegradation of hopane hydrocarbons had also taken place, with side chain oxidation.