Crude Oil Biodegradation
The bacterial strains from overnight culture (104–105 cells/ml) were transferred to 250 ml Erlenmayer flasks, each containing 100 ml of sterile mineral medium (MM) and 0.1% (v/v) of crude oil. The flasks were incubated at 30°C with continuous shaking (150 rpm) for 3 weeks.
The residual total petroleum hydrocarbons (TPH) after bacterial degradation was extracted with carbon tetrachloride (CCl4) from the liquid cultures, and analyzed by FT-IR. The interfering substances were removed by passing the extract through a column filled with Florisil. The standard substance was a mixture of 37.5% (v/v) n-hexadecane, 37.5% (v/v) isooctane and 25% (v/v) benzene, and the spectrum was recorded between the 3100-2800 cm-1 range. The absorbance value was measured at 2926 cm-1 with an IR spectrophotometer Unicam.