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BIODEGRADATION OF TRINITROTOLUENE BY IMMOBILIZED BACILLUS SP. YRE1

HAFIZ ULLAH, AAMER ALI SHAH^*, FARIHA HASAN, ABDUL HAMEED

Abstract: The present study focus on the biodegradation of trinitrotoluene (TNT) by Bacillus sp. YRE1 isolated from red effluent in free state and also cells immobilized on charcoal and polystyrene. TNT degradation was monitored weekly for 168 hours, at 262 nm. Immobilized Bacillus sp. YRE1 was checked for its ability to degrade TNT by exposing it to different temperatures. It was found that both charcoal and polystyrene immobilized bacteria degraded TNT more efficiently at 37^oC. Maximum percentage reduction in case of charcoal immobilized Bacillus sp. YRE1 at 37ºC was calculated as 73.35%. Whereas, polystyrene immobilized bacteria showed 70.58% reduction. Bacillus sp. YRE1 immobilized on charcoal, showed maximum degradation at pH 7 with 93.81% reduction in TNT. Similarly, pH 5 was found to be optimum for the degradation of TNT by polystyrene immobilized bacteria, with percentage reduction as 94%. Charcoal immobilized cells showed increased transformation with 96% reduction in the presence of Tween 20, whereas, polystyrene immobilized cultures showed 87.77% reduction in TNT.

Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.

^*Corresponding author E-mail: alishah@bs.qau.edu.pk; Tel. No. +92-51-90643185; Fax No. +9251-9219888