An acclimatized mixed microbial consortium, predominantly Burkholderia sp., was isolated from an activated sludge and investigated for its potential to degrade perchlorate in batch shake flasks. The 16S rDNA analysis of the predominant strain in the mixed culture showed the closest homology (98%) with Burkholderia sp. ATSB16. For the first time mixed culture with predominantly Burkholderia sp., has been reported to be involved in perchlorate degradation. The substrate perchlorate was completely utilized within 10 days even at a high concentration of 1000 mg L-1 utilizing succinate as the sole carbon-source. Compared to other carbon-sources tested in this study, succinate proved to be better for perchlorate degradation by the mixed consortium. The optimum conditions for perchlorate degradation by the enriched mixed culture were found to be 30 degrees C and pH 7.0. The effect of co-pollutants on perchlorate removal by the mixed culture was also investigated at a mixed perchlorate concentration of 500 mg L-1. Results showed that the degradation of perchlorate was affected to different extent due to the presence of an equal concentration (500 mg L-1 of each) of co-pollutants such as nitrate, nitrite, chlorate and phosphate. (C) 2011 Elsevier B.V. All rights reserved.