Catechol and benzoic acid are two common intermediate products in the metabolism of benzene compounds,and are also common environmental pollutants in industry wastewater. In order to efficiently remove benzene compounds from industry wastewater,the petroleum-degrading strain Acinetobacter sp. Tust-DM21 capable of effectively degrading aromatic compounds were used to investigate the degradation of catechol and sodium benzoate. The metabolic process of sodium benzoate was studied by the crude enzyme characteristics of catechol 1,2-dioxygenase（C12O）and the enzyme activity of benzoate 1,2-dioxygenase. In the inorganic salt medium without carbon source,the strain Tust-DM21 was able to grow with catechol and sodium benzoate as the sole carbon source,respectively. The characteristics of the Tust-DM21 degrading these 2 benzene compounds were studied by controlling the dosage of inoculated bacteria,substrate concentration,pH and temperature. Also the optimal pH,temperature and kinetic parameters of C12O and the enzymatic activity of benzoic acid 1,2-dioxygenase were analyzed. As results,the maximum tolerated concentration（MTC）of the strain Tust-DM21 on catechol was 700 mg/L;the optimal conditions for the strain to degrade 600 mg/L of catechol were：5% of inoculum,pH 6.0 and temperature 35℃,respectively;under the optimal condition,the bacteria degraded 92% of catechol. The MTC of the strain on sodium benzoate was 4 500 mg/L. The optimal conditions for the strain to degrade 1 500 mg/L of sodium benzoate were：3% of inoculum,pH 8.0 and temperature 35℃,respectively;under the optimal condition,the bacteria degraded 95% of sodium benzoate. The optimal conditions for the enzymatic reaction of C12O were as follows：pH 8.0 and temperature 35℃;the kinetic parameters of C12O were as follows：Km=25.68 mol/L,Vmax=0.131 mol/（mL·min）. The enzyme activity of benzoic acid 1,2-dioxygenase was 3.53 U. In conclusion,the strain Tust-DM21 has a strong capability of degrading catechol and sodium benzoate and has a broad prospective application.
