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Mechanism of oxygen availability from hydrogen peroxide to aerobic cultures of Xanthomonas campestris
Author(s) -
Sriram G.,
Sureshkumar G. K.
Publication year - 2000
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(20000220)67:4<487::aid-bit12>3.0.co;2-w
Subject(s) - protonophore , chemistry , periplasmic space , hydrogen peroxide , oxygen , flux (metallurgy) , reaction rate constant , xanthomonas campestris , catalase , biophysics , biochemistry , kinetics , membrane potential , biology , organic chemistry , enzyme , physics , escherichia coli , quantum mechanics , gene
Fundamental studies on the availability of oxygen from the decomposition of H 2 O 2 , in vivo, by Xanthomonas campestris , when H 2 O 2 is used as an oxygen source are presented. It was found that the H 2 O 2 added extracellularly (0.1–6 m M ) was decomposed intracellularly. Further, when H 2 O 2 was added, the flux of H 2 O 2 into the cell, is regulated by the cell. The steady‐state H 2 O 2 flux into the cell was estimated to be 9.7 × 10 −8 mol m −2 s −1 . In addition, it was proved that the regulation of H 2 O 2 flux was coupled to the protonmotive force (PMF) using experiments with the protonophore carbonyl cyanide m ‐chlorophenylhydrazone (CCCP), which disrupts PMF. The coupling constant between the rate of free energy availability from PMF and the rate of reduction of H 2 O 2 flux, was found to be 46.4 mol m −2 s −1 J −1 from simulations using a developed model. Also, the estimated periplasmic catalase concentration was 1.4 × 10 −9 M . © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 67: 487–492, 2000.