Enrichment of a microbial culture capable of degrading endosulphate, the toxic metabolite of endosulfan

• Published in: Journal of applied microbiology Vol. 92; no. 3; pp. 541 - 548
• Main Authors: Sutherland, T.D., Weir, K.M., Lacey, M.J., Horne, I., Russell, R.J., Oakeshott, J.G.
• Format: Journal Article
• Language: English
• Published: Oxford UK Blackwell Science Ltd 01.03.2002; Blackwell Science; Oxford University Press
• Subjects: Bacteria - growth & development; Bacteria - isolation & purification; Bacteria - metabolism; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Biotechnology; Chromatography, Thin Layer; Culture Media; Endosulfan - analogs & derivatives; Endosulfan - metabolism; Environment and pollution; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry; Hydrocarbons, Chlorinated; Industrial applications and implications. Economical aspects; Insecticides - metabolism; Soil Microbiology; Biodegradation; Enrichment; Insecticide; Metabolite; Organochlorine compounds; Pesticides; Microorganism culture; Bioremediation
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1046/j.1365-2672.2002.01559.x

Aims: The aim of this study was to isolate a source of enzymes capable of degrading endosulphate (endosulfan sulphate), the toxic metabolite of the pesticide endosulfan. Methods and Results: A microbial broth culture capable of degrading endosulphate was enriched from endosulfan‐contaminated soil by providing the metabolite as the sole source of sulphur in broth culture. No microbial growth was observed in the absence of endosulphate. In the presence of endosulphate, growth of the culture occurred with the concomitant formation of three chlorine‐containing compounds. Thin layer chromatography and gas chromatography–mass spectral analysis identified these metabolites as endosulfan monoaldehyde, 1,2,3,4,7,7‐hexachloro‐5,6‐bis(methylene)bicyclo[2.2.1]‐2‐heptene and 1,2,3,4,7,7‐hexachloro‐5‐hydroxymethylene‐6‐methylenebicyclo[2.2.1]‐2‐heptene. The second and third compounds have not been reported in previous metabolic studies. The enriched culture was also able to utilize α‐ and β‐endosulfan as sulphur sources, each producing the hydrolysis product endosulfan monoaldehyde as the sole chlorine‐containing metabolite. Alpha‐endosulfan was more readily hydrolysed than the β‐isomer. Conclusions: This study isolated a mixed microbial culture capable of degrading endosulphate. The products of degradation were characterized as novel endosulfan metabolites. Significance and Impact of the Study: This study describes the isolation of a mixed microbial culture that is potentially a valuable source of hydrolysing enzymes for use in enzymatic bioremediation, particularly of endosulphate and α‐endosulfan residues.