Effects of the addition of organic carbon sources on bacterial respiration and n-alkane biodegradation of Omani crude oil

Respirometry and gas chromatography showed that, in the presence of crude oil, the surfactants Corexit® 9527 and Corexit® 9130 were rapidly oxidized by Pseudomonas aeruginosa alone and by a mixed culture of bacteria. The addition of a mineral fertilizer to the oil was ineffective in increasing respiration or alkane breakdown. When cane sugar molasses was added to the oil, respiration increased markedly and was associated with significant n-alkane breakdown. The bacterial counts at the start and end of the respirometry showed no significant variations whichever substrates were metabolized by the bacteria. The significance of the addition of organic substrates to oil in relation to biodegradation of alkanes is discussed.