Isolation, Screening and Selection of Efficient Chlorpyriphos Degrading Microorganisms
KrishiKosh
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Title |
Isolation, Screening and Selection of Efficient Chlorpyriphos Degrading Microorganisms
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Creator |
Anuja George
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Contributor |
K.S.Jagadeesh
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Subject |
Agricultural Microbiology
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Description |
The focus of the present study was to develop bacteria capable of bioremediation of chlorpyriphos contaminated soil. This was attempted by isolating 28 bacterial isolates from chlorpyriphos enriched soil samples and screening for biodegradation of the pesticide. Of the screened bacterial isolates, 13 grew on mineral salts medium containing 100 ppm chlorpyriphos as the sole carbon source. There was only a slight increase in the release of chloride when the medium was supplemented with additional carbon sources such as succinic acid, glucose and maltose (@ 1 g/l). The most promising chlorpyriphos degrading bacteria were Pseudomonas sp. JA 15 and Enterobacter sp. JA 8 which degraded the pesticide by 98 and 93 per cent respectively in 7 days. Calcium alginate-immobilized Pseudomonas JA15 strain resulted in complete degradation of chlorpyriphos by 100 hours. Thin layer chromatographic analysis of all the isolates revealed appearance of an unknown metabolite having Rf value in the range 0.15-0.19. The enzyme involved in chlorpyriphos degradation by Pseudomonas JA15 isolate was found to be extracellular. These efficient strains were selected for the bioremediation of chlorpyriphos contaminated soil. The bioaugmentation of the strains alone and in combination to the contaminated soil resulted in higher degradation rate than was observed in uninoculated soils. The phytotoxic effects of the pesticide on germination and growth of cowpea were counteracted by the strains. The population of chlorpyriphos degrading bacteria in the polluted soil was found to increase throughout the period of investigation due to breakdown of the pesticide. The seed inoculation technique proved to be a promising method of delivering the strain for the bioremediation of chlorpyriphos contaminated soil, as cowpea root exudates supported the growth and multiplication of JA 15 strain. |
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Date |
2016-10-17T10:46:23Z
2016-10-17T10:46:23Z 2005 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/80658
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Format |
application/pdf
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Publisher |
UAS, Dharwad
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