Abstract:
Polycyclic aromatic hydrocarbons (PAHs) are released into the environment through natural activities such as
forest fires and incomplete combustion of wood and decay of vegetable matter. Anthropogenic activities that
release PAHs into the environment include activities such as combustion of coal and petroleum product
processing. PAHs are not easily accessible to bacteria for degradation due to their low solubility in water. Among
the notorious PAH are the high ring number PAHs (ring-number 4 - 7) that are extremely difficult to degrade due
to their hydrophobicity which renders them insoluble in water. One such compound, fluoranthene (Flu), is a four
ring PAH classified as a High Molecular Weight (HMW) compound. Due to the difficulty to degrade these
compounds, it is necessary to find novel and environmentally compatible methods for treating them. In this
study, PAH degrading organisms isolated from engine oil contaminated soil achieved 92 % removal of Flu in a
fixed-film bioreactor operated at retention time of 1.19 h at 0.86 L.h-1 under fully submerged conditions. The
predominant species of biosurfactant producing bacteria in the reactor were determined to be dominated by
Pseudomonas aeruginosa using 16S rRNA genotype fingerprinting analysis.
