• Journal of Life Science
• /
• v.16 no.1
• /
• pp.108-113
• /
• 2006

To compensate the problems of chemical assay in detoxification of recalcitrant and a practical approach in selection of bioremediation bacteria, a simple and rapid toxicity evaluation system was constructed based on Lumbricus rubellus. Long term-culture and specific equipment are not necessary, and semi-quantitative analysis of toxicity at sub-lethal concentration is possible by measuring of dose-dependent increased yellowish secreted compounds. When the toxicity of endosulfan, its metabolites and structurally related chemicals were measured for 24 h, the results were coincided with previous reports. Toxicity was found in endosulfan, endosulfan sulfate, aldrin, and dieldrin, respectively. Rapid and economic selection of endosulfan-detoxifying bacteria was possible using our system. Klebsiella pneumoniae KE-1, K. oxytoca KE-8 and Pseudomonas sp. KS-2P, reported endosulfan degrading bacteria, ameliorated the endosulfan toxicity, whereas E. coli, B. subtilis and other bacteria failed to protect the toxicity of endosulfan in L. rubellus. Our results suggest that the constructed system is useful to selection of microorganism as well as toxicity evaluation against toxic recalcitrants.

• Food Science and Preservation
• /
• v.19 no.3
• /
• pp.451-454
• /
• 2012

Endosulfan is an organochlorine pesticide that is widely used throughout the world for higher agricultural production. Its extreme toxicity, however, has caused health and environment concerns that have led to an interest in detoxification. In this study, the radiolytic degradation of endosulfan was investigated. Endosulfan in methanol solution (100 ppm) was irradiated at 0, 10, 30, and 50 kGy, and subsequent changes in immune toxicity and degradation of endosulfan were observed. The concentration of endosulfan that was used in this experiment did not affect the cell proliferation. The irradiation of endosulfan decreased the production of NO, indicating a decrease in the immune toxicity of endosulfan by irradiation. The concentration of endosulfan was significantly reduced by irradiation in a dose-dependent manner. The results suggest that gamma irradiation can degrade endosulfan and can reduce its immune toxicity.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.2
• /
• pp.202-208
• /
• 2011

BACKGROUD: ${\alpha}$- and ${\beta}$- Endosulfan isomers of endosulfan, an endocrine disrupting chemical, are widely used cyclodiene organochlorine pesticide in worldwide, and it has widespread application in agriculture and can contaminate river-system as runoff from soil or aerial deposition METHOD AND RESULTS: In this study, an attempt was made to isolate an endosulfan degrading fungus from endosulfan-polluted agricultural soil. Through repetitive enrichment and successive subculture in media containing endosulfan and its metabolites as the sole carbon source, a fungus designated KEF-1 was isolated. Based on phylogenetic analysis, strain KEF-1 was assigned to the genus Eutypella. Also, the ITS (internal transcribed spacer) sequences of KEF-1 were submitted to GenBank under accession number EF581006. In potato dextrose broth containing 8 ${\mu}g$/mL endosulfan, strain KEF-1 completely degraded the endosulfanin 12 days. CONCLUSION: These results suggested that Eutypella sp. KEF-1 has potential as a biocatalyst for endosulfan bioremediation

• Applied Biological Chemistry
• /
• v.37 no.3
• /
• pp.194-202
• /
• 1994

To study the metabolism and absorption of endosulfan in carp, $^{14}C-{\alpha}-endosulfan$ was treated with the $LC_{10}$ concentration $(4.5\;{\mu}g/L)$. In an in vivo test, endosulfan was metabolized $(65{\sim}80%)$ in tissues and endosulfan ether, endosulfan alcohol, endosulfan ${\alpha}-hydroxyether$, and endosulfan lactone were identified, indicating that those are the main metabolites of detoxification in carp. The maximum levels of $^{14}C-endosulfan$ in the head, muscle, and gut occurred after 8 hr exposure. However, the maxima reached in the liver and kidneys after 30 min and 4 hr, respectively. Radioactivity in the tissue decreased rapidly 8 hr after treatment. The total amount of $^{14}C-endosulfan$ recovered in the liver, kidneys and gut of fish was about $80{\sim}90%$ during the 8 hr treatment. The non-extractable radioactivity increased after 8 hr exposure $(27{\sim}31%)$. Endosulfan sulfate, the main degradation product in plant and mouse, was not detected during the test interval from tissues of the carp.

• Korean Journal of Environmental Agriculture
• /
• v.29 no.2
• /
• pp.176-183
• /
• 2010

Endosulfan degrading ability of Klebsiella oxytoca KE-8 immobilized by entrapment with activated carbon was examined. Endosulfan degradation by the immobilized bacterial strains on several different activated carbon based support materials was investigated. Based on results, activated carbon ($8\times30$ mesh) was chosen as a support material. The immobilized Klebsiella oxytoca KE-8 with the cell density of 4 mg $g^{-1}$ (dry weight) degraded 22.18 ug $ml^{-1}$ endosulfan within 5 days at pH 7.0, $30^{\circ}C$ in batch shake flask cultures. Also, we an experimented recycle packed bed column mode and continuous packed bed column mode for endosulfan degradation. Under optimum operation condition, the immobilized cells in a laboratory scale pack bed column with support beads were able to degrade endosulfan completely in defined minimal salt medium at a maximum rate of 129.6 ug $ml^{-1}$ per day. Moreover, the endosulfan degradation activity could be demonstrated at $4^{\circ}C$ for one month without significant decrease in activity. Results of this study suggest that immobilized cells of Klebsiella oxytoca KE-8 might be applicable to endosulfan contaminated site.