with some minor modifications. For the preparation of this medium, the main solution was made anaerobically and autoclaved separately, containing 816 mg/L KH2PO4 and 5920 mg/L K2HPO4, 530 mg/L NH4Cl, 200 mg/L MgSO4, 1000 mg/L KNO3, 25 mg/L CaCl2 x H2O. After autoclaving, the medium was supplemented with 10 mL/L trace elements, 5 mL/L vitamins solution and 1 mL/L sodium selenite/sodium tungstate stock solution, stock solutions were (1000 x). The precultures of Aromatoleum sp. were prepared in Thb medium supplemented with 4 mM sodium benzoate, allowing the bacteria to reach the stationary stage before inoculating it into a medium with 0.025 % toluene in a larger volume (1-2 L). To prevent toluene toxicity, paraffin oil was added to the medium in the final concentration of 2%. Further on, the culture was supplemented with 0.1% toluene in the final volume when needed, based on monitoring nitrate and nitrite levels, assuming a 1:4 ratio of toluene and nitrate consumption.