Action of inhibitors on hydrogenase in Azotobacter

Journal Article · Fri Jan 01 04:00:00 EDT 1943 · J. Gen. Physiol.; (United States)

DOI:https://doi.org/10.1085/jgp.26.3.277· OSTI ID:6758783

Wilson, J B; Wilson, P W

The inhibitors usually associated with the activity of the cytochrome oxidase system - cyanide and carbon monoxide - are also effective in reducing the oxidation of H/sub 2/ by intact cells of Azotobacter vinclandii. The hydrogenase system is more sensitive to CO than is the respiratory system. Oxidation of a carbon source and of hydrogen by Azotobacter cells is inhibited in a quantitatively different manner by the following compounds: sodium azide, hydroxylamine, sodium iodoacetate, and sodium fluoride. In every case, a concentration range which is definitely inhibitory for respiration has little or no effect on the hydrogenase activity. The differential inhibition by hydroxylamine explains certain observations in the literature which have been erroneously interpreted as demonstrating a specific inhibition by NH/sub 2/OH of biological nitrogen fixation. This supposed demonstration has been offered as support for the hypothesis that NH/sub 2/OH is an intermediate in the fixation reaction. The differential inhibitors can be used for detection of hydrogenase in cultures possessing a high endogenous respiration. The method is illustrated by an experiment with root nodule bacteria from pea and cowpea nodules. No hydrogenase was found in either. 8 references, 4 figures, 4 tables.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 6758783
• Journal Information: J. Gen. Physiol.; (United States), Journal Name: J. Gen. Physiol.; (United States) Vol. 26; ISSN JGPLA
• Country of Publication: United States
• Language: English

Related Subjects

510200* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AZOTOBACTER
BACTERIA
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CYANIDES
ELEMENTS
ENZYME INHIBITORS
ENZYMES
FOOD
HYDROGEN
HYDROGENASES
MICROORGANISMS
NONMETALS
OXIDATION
OXIDES
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PEAS
PLANTS
RESPIRATION
SOILS
VEGETABLES