Nitrogen Fixation and Hydrogen Metabolism in Relation to the Dissolved Oxygen Tension in Chemostat Cultures of the Wild Type and a Hydrogenase-Negative Mutant of Azorhizobium caulinodans
| Autor: | Fred Boogerd, Ferdinandy-Van Vlerken, M. M., Mawadza, C., Pronk, A. F., Stouthamer, A. H., Verseveld, H. W. |
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| Přispěvatelé: | Molecular Cell Physiology, AIMMS |
| Jazyk: | angličtina |
| Rok vydání: | 1994 |
| Předmět: | |
| Zdroj: | Boogerd, F C, Ferdinandy-van Vlerken, M M, Mawadza, C, Pronk, A F, Stouthamer, A H & van Verseveld, H W 1994, ' Nitrogen Fixation and Hydrogen Metabolism in Relation to the Dissolved Oxygen Tension in Chemostat Cultures of the Wild Type and a Hydrogenase-Negative Mutant of Azorhizobium caulinodans ', Applied and Environmental Microbiology, vol. 60, no. 6, pp. 1859-66 . Vrije Universiteit Amsterdam Applied and Environmental Microbiology, 60(6), 1859-66. American Society for Microbiology |
| ISSN: | 0099-2240 |
| Popis: | Both the wild type and an isogenic hydrogenase-negative mutant of Azorhizobium caulinodans growing ex planta on N(2) as the N source were studied in succinate-limited steady-state chemostat cultures under 0.2 to 3.0% dissolved O(2) tension. Production or consumption of O(2), H(2), and CO(2) was measured with an on-line-connected mass spectrometer. In the range of 0.2 to 3.0%, growth of both the wild type and the mutant was equally dependent on the dissolved O(2) tension: the growth yield decreased, and the specific O(2) consumption and CO(2) production increased. A similar dependency on the dissolved O(2) tension was found for the mutant with 2.5% H(2) in the influent gas. The H(2)/N(2) ratio (moles of H(2) evolved per mole of N(2) consumed via nitrogenase) of the mutant, growing with or without 2.5% H(2), increased with increasing dissolved O(2) tensions. This increase in the H(2)/N(2) ratio was small but significant. The dependencies of the ATP/N(2) ratio (moles of ATP consumed per mole of N(2) fixed) and the ATP/2e ratio [moles of ATP consumed per mole of electron pairs transferred from NAD(P)H to nitrogenase] on the dissolved O(2) tension were estimated. These dependencies were interpreted in terms of the physiological concepts of respiratory protection and autoprotection. |
| Databáze: | OpenAIRE |
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