Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1058981 | Journal of Environmental Management | 2006 | 8 Pages |
Abstract
The growth properties and biodegradation mechanism of a Gram-negative bacterium, Pseudomonas nitroreducens TX1 that was able to grow on branched octylphenol polyethoxylates (OPEOn, average n=9.5) as the sole carbon source over a wide concentration range (1-100,000 mg lâ1) were studied. Analysis of growth factors indicated the highest specific growth rate (μ) of 0.53 hâ1 was obtained at an initial concentration of 5000 mg lâ1 OPEOn. An optimal C/N ratio of 12 was obtained for (NH4)2SO4 as the nitrogen source in a cultivated medium at pH 7. The kinetic analysis demonstrated that bacterial growth and OPEOn degradation followed the Monod equation and were based on a substrate concentration inhibition model and pseudo-first-order reaction, respectively. The substrate inhibition coefficient was over 18,000 mg lâ1 and this indicates that the strain has an ability to sustain growth at high concentrations of OPEOn and use it as the sole carbon source under such a stress condition. Furthermore, LC-MS analysis showed that the biodegradation mechanism of dodecyl octaethoxylate (AEO8) by P. nitroreducens TX1 was the sequential cleavage of the ethoxylate chain.
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Authors
Hsi-Jien Chen, Gia-Luen Guo, Dyi-Hwa Tseng, Chen-Li Cheng, Shir-Ly Huang,