Environmental biology

Biodegradation of organochlorine pesticide endosulfan by bacterial strain Alcaligenes faecalis JBW4

Lingfen Kong , Shaoyuan Zhu , Lusheng Zhu , Hui Xie , Kunchang Su , Tongxiang Yan , Jun Wang , Jinhua Wang , Fenghua Wang , Fengxia Sun


Received January 06, 2013,Revised March 07, 2013, Accepted , Available online November 01, 2013

Volume ,2013,Pages 2257-2264

The recently discovered endosulfan-degrading bacterial strain Alcaligenes faecalis JBW4 was isolated from activated sludge. This strain is able to use endosulfan as a carbon and energy source. The optimal conditions for the growth of strain JBW4 and for biodegradation by this strain were identified, and the metabolic products of endosulfan degradation were studied in detail. The maximum level of endosulfan biodegradation by strain JBW4 was obtained using broth at an initial pH of 7.0, an incubation temperature of 40℃ and an endosulfan concentration of 100 mg/L. The concentration of endosulfan was determined by gas chromatography. Strain JBW4 was able to degrade 87.5% of α-endosulfan and 83.9% of β-endosulfan within 5 days. These degradation rates are much higher than the previously reported bacterial strains. Endosulfan diol and endosulfan lactone were the major metabolites detected by gas chromatography-mass spectrometry; endosulfan sulfate, which is a persistent and toxic metabolite, was not detected. These results suggested that A. faecalis JBW4 degrades endosulfan via a non-oxidative pathway. The biodegradation of endosulfan by A. faecalis is reported for the first time. Additionally, the present study indicates that strain JBW4 may have potential for the biodegradation of endosulfan residues.

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