Regulation of nitrogenase activity by oxygen in Azospirillum brasilense and Azospirillum lipoferum
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Regulation of nitrogenase activity by oxygen in Azospirillum brasilense and Azospirillum lipoferum.
The nitrogenase activity of the microaerophilic bacteria Azospirillum brasilense and A. lipoferum was completely inhibited by 2.0 kPa of oxygen (approximately 0.02 atm of O2) in equilibrium with the solution. The activity could be partially recovered at optimal oxygen concentrations of 0.2 kPa. In contrast to the NH4+ switch off, no covalent modification of the nitrogenase reductase (Fe protein...
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The microaerophilic nitrogen-fixing bacterium Azospirillum brasilense formed a sharply defined band in a spatial gradient of oxygen. As a result of aerotaxis, the bacteria were attracted to a specific low concentration of oxygen (3 to 5 microM). Bacteria swimming away from the aerotactic band were repelled by the higher or lower concentration of oxygen that they encountered and returned to the ...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 1987
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.169.3.944-948.1987