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BIODEGRADATION OF 4-AMINOBENZENE SULPHONIC ACID BY A LOCAL TEXTILE MILL ASPERGILLUS NIGER ISOLATE

R. FARYAL**¹, S. AHMED** AND A. HAMEED*

Abstract: 4-aminobenzene sulphonic acid (4-ABS) is an intermediate formed during the degradation of azo dye loaded effluent containing the unutilized azo dyes used by the textile industry during dyeing and printing processes. Released in the environment, it is a recalcitrant and mutagen. Degradation of 4ABS by fungal strain Aspergillus niger RH19 was investigated in batch shake flask-cultures. Aspergillus niger RH19 showed more than 40% degradation of 4ABS. Experiments were carried out at initial concentrations between 50-500mg L^-1. With increasing initial 4ABS concentrations in shake-flask cultures, percentage removal of 4ABS decreased and residual 4ABS concentrations increased proportionally. Temperature, pH and inoculum size for degradation were optimized. Optimum temperature and pH for degradation was 34oC and 5.0 respectively. Degradation in shaking condition at various concentrations of 4ABS (50-500 mg L^-1) was 30-60% whereas in static condition degradation was <20%. Degradation of 4ABS was not affected with addition of glucose as secondary source of carbon at 250mg L^-1, however at 500mg L^-1, addition of glucose resulted in decreased degradation.

* Department of Biosciences, COMSATS Institute of Information Technology, Bio-Physics Block, Johar Campus, Islamabad, Pakistan.
** Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan.

¹Corresponding Author: ranifaryal@comsats.edu.pk