INITIAL TRANSFORMATIONS IN THE BIODEGRADATION OF BENZOTHIAZOLES BY RHODOCOCCUS ISOLATES

Benzothiazole-2-sulfonate (BTSO3) is one of the side products occurrin g in 2-mercaptobenzothiazole (MBT) production wastewater. We are the f irst to isolate an axenic culture capable of BTSO3 degradation. The is olate was identified as a Rhodococcus erythropolis strain and also deg raded 2-hydroxybenzothiazole (OBT) and benzothiazole (BT), but not MET , which was found to inhibit the biodegradation of OBT, BT, and BTSO3. In anaerobic resting cell assays, BTSO3 was transformed into OBT in s toichiometric amounts. Under aerobic conditions, OBT was observed as a n intermediate in BT breakdown and an unknown compound transiently acc umulated in several assays. This product was identified as a dihydroxy benzothiazole. Benzothiazole degradation pathways seem to converge int o OBT, which is then transformed further into the dihydroxy derivative .