Growth factors, kinetics and biodegradation mechanism associated with Pseudomonas nitroreducens TX1 grown on octylphenol polyethoxylates.
The growth properties and biodegradation mechanism of a Gram-negative bacterium, Pseudomonas nitroreducens TX1 that was able to grow on branched octylphenol polyethoxylates (OPEO(n), average n=9.5) as the sole carbon source over a wide concentration range (1-100,000 mgl(-1)) were studied. Analysis of growth factors indicated the highest specific growth rate (micro) of 0.53 h(-1) was obtained at an initial concentration of 5,000 mgl(-1) OPEO(n). An optimal C/N ratio of 12 was obtained for (NH(4))(2)SO(4) as the nitrogen source in a cultivated medium at pH 7. The kinetic analysis demonstrated that bacterial growth and OPEO(n) 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 mgl(-1) and this indicates that the strain has an ability to sustain growth at high concentrations of OPEO(n) 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.
Chen
Hsi-Jien
HJ
Graduate Institute of Environmental Engineering, National Central University, Chung-Li, Taiwan, ROC. hjchen@mail.ev.ncu.edu.tw
Guo
Gia-Luen
GL
Tseng
Dyi-Hwa
DH
Cheng
Chen-Li
CL
Huang
Shir-Ly
SL
D049109:Cell Proliferation; D006863:Hydrogen-Ion Concentration; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007700:Kinetics; D013058:Mass Spectrometry; D015394:Molecular Structure; D009584:Nitrogen / Q000378:metabolism; D010880:Piperidines / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D011549:Pseudomonas / Q000166:cytology* / Q000378:metabolism*
D036341:Intercellular Signaling Peptides and Proteins; D010880:Piperidines; D011108:Polymers; C039611:octapinol; D009584:Nitrogen