Bioremediation of the anionic surfactant linear Alkylbenzene sulphate (LAS) by pseudomonas SP isolated from soil
Shodhganga@INFLIBNET
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Title |
Bioremediation of the anionic surfactant linear Alkylbenzene sulphate (LAS) by pseudomonas SP isolated from soil
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Contributor |
Jish, M S
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Subject |
Histopathology
Linear alkylbenzene sulphonates (LAS) xenobiotics biodegradation Pseudomonas sp. immobilised cells diauxic growth biofilm biosurfactant rhamnolipid |
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Description |
Linear alkylbenzene sulphonate (LAS) are the most commonly employed anionic surfactants. Large quantities of detergents and their components are released into aquatic and terrestrial environments after use. LAS is regarded as a readily biodegradable product under aerobic conditions. Usually degradation rates are influenced by the initial LAS concentration in the sludge and environmental parameters such as pH, soil moisture, or organic matter content. The aim of this study was to isolate potential LAS degrading organisms and study various factors determining efficiency of LAS degradation by the selected isolates. After soil enrichment 20 LAS degrading cultures were isolated. After screening the isolates by checking the ability to degrade LAS two isolates were selected (L9 and L12) for further studies. The selected cultures showed about 99% reduction in peak area after 15 days of incubation, when culture supernatant was analysed with High performance liquid chromatography (HPLC). The selected organisms were identified as Pseudomonas nitroreducens (MTCC 10463) and P. aeruginosa (MTCC 10462). The 16S rDNA sequence of the isolates were deposited in Gene Bank and got the accession number HQ271083 (L9) and HQ271084 (L12). Antibiotic sensitivity profile of the organisms showed that both the isolates were sensitive to gentamycin and resistant to ampicillin. The isolates harbors plasmids and it was found that plasmid cured isolates were able to grow in mineral salt media with LAS as sole carbon source, where they exhibited a slow growth. Efficiency of LAS degradation by the selected isolates was influenced by factors like pH, temperature, surfactant concentration, aeration etc. Metabolic intermediates were detected using FTIR and GC-MS analysis of the culture supernatant. In GC-MS analysis, presence of sulphophenyl carboxilyic acids, the major LAS degradation intermediates, were analysed. The selected strains were screened for biosurfactant production by culturing on Siegmund- Wagner media and blood agar.
References p.217-276, Appendix p.277-285 |
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Date |
2013-11-22T11:26:36Z
2013-11-22T11:26:36Z 2013-11-22 n.d. January, 2011 n.d. |
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Type |
Ph.D.
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Identifier |
http://hdl.handle.net/10603/13164
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Language |
English
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Relation |
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Rights |
university
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Format |
285p.
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Coverage |
Chemistry
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Publisher |
Kottayam
Mahatma Gandhi University Faculty of Science |
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Source |
INFLIBNET
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