Oxygen supply without gas-liquid film resistance to Xanthomonas campestris cultivation
DSpace at IIT Bombay
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Title |
Oxygen supply without gas-liquid film resistance to Xanthomonas campestris cultivation
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Creator |
SRIRAM, G
RAO, YM SURESH, AK SURESHKUMAR, GK |
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Subject |
oryzae pv oryzae
monofunctional catalase fermentation broths xanthan production mass-transfer dna-damage growth batch temperature mechanism oxygen-supply bioreactors h2o2 decomposition xanthomonas catalase hocl pretreatment |
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Description |
Alternative methods of oxygen supply are of crucial importance, especially in viscous fermentations and shear-sensitive fermentations. A method of oxygen supply that completely eliminates the gas-liquid transport resistance has been presented. The method involves a need-based liquid-phase decomposition of hydrogen peroxide to provide the necessary oxygen. When Xanthomonas campestris was cultivated (viscous cultivation) using this method of oxygen supply, dissolved oxygen (DO) levels were maintained above the setpoint of 50% throughout the cultivation, whereas the conventional cultivation was able to meet culture oxygen demand only for about 6 h in a 72-h fermentation. Furthermore, the maximum specific growth rate and xanthan yields in the novel cultivation were 89% and 169%, respectively, of those obtained in conventional cultivation. A mathematical model was also developed to simulate and predict results in fermentations employing the presented methodology. In addition, studies with HOCl pretreatments indicated that monofunctional catalase may be responsible for the decomposition of H2O2 supplied externally to cells; HOCl pretreatments also increased the tolerance of cells to H2O2. The decomposition kinetics of externally supplied H2O2 was Michaelis-Menlen in nature with v(max) = 1.196 x 10(-6) M s(-1) and K-m = 0.21 mM. The catalase concentration was estimated to be 3.4 x 10(-10) mol/g of cells. (C) 1998 , Inc.
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Publisher |
JOHN WILEY & SONS INC
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Date |
2011-08-16T11:35:22Z
2011-12-26T12:54:55Z 2011-12-27T05:43:20Z 2011-08-16T11:35:22Z 2011-12-26T12:54:55Z 2011-12-27T05:43:20Z 1998 |
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Type |
Article
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Identifier |
BIOTECHNOLOGY AND BIOENGINEERING, 59(6), 714-723
0006-3592 http://dx.doi.org/10.1002/(SICI)1097-0290(19980920)59:6<714::AID-BIT8>3.0.CO;2-I http://dspace.library.iitb.ac.in/xmlui/handle/10054/9488 http://hdl.handle.net/10054/9488 |
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Language |
en
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