Biodegradation of pyrene by a mixed culture isolated from hydrocarbon-polluted soil

This paper presents the biodegradation of pyrene (C16H10), a four-benzene-ring polycyclic aromatic hydrocarbon (PAHs) using a mixed culture of bacteria. The mixed culture was enriched from hydrocarbon-polluted soil sample, using a plate incubated with a thin film of pyrene. The isolates were identified biochemically as Bacillus cereus and Enterobacter aerogenes. The mixed culture bacteria degraded approximately 90% of the pyrene in aqueous medium within six days of incubation. The assessment of other environmental factors necessary for the activity of the mixed culture revealed that the mixed culture grows well between pH of 5.0-7.0 and temperatures of between 20-30°C. From the results of this trial therefore, it is suggested that the mixed culture has good potential for bioremediation applications.   Key words: Pyrene, biodegradation, mixed culture, polycyclic aromatic hydrocarbon (PAHs), environmental factors.