ISSN:
1432-072X
Keywords:
Rhizobium
;
French-bean
;
Bacteroid
;
C2H2 reduction
;
Oxygen uptake
;
Cytochrome c
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Low concentration of dissolved O2 (3 μM) induced a significant C2H2 reduction by bacteriods isolated from French-beans (Phaseolus vulgaris) inoculated with Rhizobium phaseoli strain 9-6. This activity, determined with or without glucose, declined with increasing O2 concentrations in spite of the generation of a substantial level of ATP. Under these conditions, cytochrome c studied by a rapid spectrometry method on whole cells, appeared more than 80% oxidized. An active C2H2 reduction always corresponded to a high level of cyt c reduction observed with glucose, at low O2 tensions only, and with succinate for a larger range of pO2 values. Our results indicated that inability of glucose to support C2H2 reduction activity for higher O2 tensions was due to a limiting electron allocation to nitrogenase in relation with the poor level of reduced cyt c observed in these conditions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00407755
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