Tolerance and Biodegradation of Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) by a Metal Acclimatized Bacterial Consortium Culture

This investigation reports the tolerance and biodegradation of benzene, toluene, ethylbenzene and xylene isomers (BTEX) by a heavy metal-adapted environmental bacterial consortium, known as consortium culture (CC). Higher tolerance was observed with benzene (IC50 value up to 191.25 mg/L), followed by toluene (IC50 = 139.67 mg/L), xylene (IC50 = 97.04 mg/L) and ethylbenzene (IC50 =96.99 mg/L). Significant decrease (p < 0.05) in the specific growth rate (µ), however was observed as the concentrations of each individual BTEX were increased from 10 mg/L to 500 mg/L. Growth of CC was completely inhibited at 250 mg/L ethylbenzene and 500 mg/L xylene. Toxicity followed the trend: B T>X>E.