Benzene utilization as growth substrate by a newly isolated Aerococcus sp. strain BPD-6 indigenous to petroleum hydrocarbon contaminated oily sludge

Monoaromatic hydrocarbons such as benzene have been found in sludge created by oil production facilities and industries. Benzene is considered as a carcinogenic substrate and biodegradation, primarily under aerobic conditions, is an important environmental process for water and soil associated benzene remediation. Aerococcus sp. strain BPD-6 isolated from petroleum hydrocarbon contaminated oily sludge was characterized in terms of its growth in presence of benzene (50–1000 mg L) as the sole carbon and energy source in mineral salts medium. The growth kinetics of the strain was analysed and the Haldane model was found to be a good fit for the experimental data with kinetic constants maximum specific growth rate (μmax) = 0.02157 h, half saturation constant Ks = 19.56 mg L and substrate inhibition constant Ki = 1584 mg L. The biodegradation rate kinetic parameter was obtained for the first order kinetic model and thus the results indicate that this Gram-positive strain can potentially be utilized in bioremediation of benzene containing oily sludge.