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Abstract: Perchloroethylene (PCE) is a major environmental pollutant that often persists in the subsurface soil and it highly recalcitrant under aerobic degradation. In this work we have isolated PCE degrading bacterial strain JSK1 from dry cleaning industrial sludge using anaerobic culture technique. Biochemical, physiological and morphological studies showed that the organism is rod shaped, highly motile, endospore forming, catalase positive and gram positive. 16S rRNA sequence of the strain showed a homology of 99% with Bacillus sp. IMR-B317 and confirmed as Bacillus sp. The strain JSK1 is able to tolerate PCE at concentration as high as 10 mM and degradation rates up to 2 mM. The rate of degradation of PCE via Trichloroethylene (TCE) to cis-1,2-Dichloroethylene (DCE) was 2.7 μmol of PCE·h-1 mg (dry weight) of cells-1. The effect of electron donors for PCE degradation was studied with various electron donors instead of yeast extract. The organism showed the ability to degrade PCE in the presence of acetate, pyruvate, lactate, formate and glucose. The effectiveness of strain JSK1 in the biodegradation of PCE was observed under variable pH and temperature conditions. The maximum degradation was observed at pH 7.5 and temperature 30ºC respectively. These results indicated that, the strain JSK1 have great potential for remediation of soils contaminated with PCE.

Keyword: Bacillus sp., Enrichment culture, Electron donors, Industrial sludge, Perchloroethylene