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Title: Evaluation of nitrate reductase activity in Rhizobium japonicum

Abstract

Nitrate reductase activity was evaluated by four approaches, using four strains of Rhizobium japonicum and 11 chlorate-resistant mutants of the four strains. It was concluded that in vitro assays with bacteria or bacteroids provide the most simple and reliable assessment of the presence or absence of nitrate reductase. Nitrite reductase activity with methyl viologen and dithionite was found, but the enzyme activity does not confound the assay of nitrate reductase. 18 references

Authors:
;
Publication Date:
Research Org.:
Dept. of Agronomy, Ohio State Univ. and Ohio Agricultural Research and Development Center, Wooster, OH 44691
OSTI Identifier:
5216055
Resource Type:
Journal Article
Resource Relation:
Journal Name: Appl. Environ. Microbiol.; (United States); Journal Volume: 46:2
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; MYCORRHIZAS; ENZYME ACTIVITY; NITROGEN FIXATION; IN VITRO; INHIBITION; MUTANTS; NITRATES; OXIDOREDUCTASES; SYMBIOSIS; ENZYMES; NITROGEN COMPOUNDS; OXYGEN COMPOUNDS 550700* -- Microbiology

Citation Formats

Streeter, J.G., and DeVine, P.J.. Evaluation of nitrate reductase activity in Rhizobium japonicum. United States: N. p., 1983. Web.
Streeter, J.G., & DeVine, P.J.. Evaluation of nitrate reductase activity in Rhizobium japonicum. United States.
Streeter, J.G., and DeVine, P.J.. 1983. "Evaluation of nitrate reductase activity in Rhizobium japonicum". United States. doi:.
@article{osti_5216055,
title = {Evaluation of nitrate reductase activity in Rhizobium japonicum},
author = {Streeter, J.G. and DeVine, P.J.},
abstractNote = {Nitrate reductase activity was evaluated by four approaches, using four strains of Rhizobium japonicum and 11 chlorate-resistant mutants of the four strains. It was concluded that in vitro assays with bacteria or bacteroids provide the most simple and reliable assessment of the presence or absence of nitrate reductase. Nitrite reductase activity with methyl viologen and dithionite was found, but the enzyme activity does not confound the assay of nitrate reductase. 18 references},
doi = {},
journal = {Appl. Environ. Microbiol.; (United States)},
number = ,
volume = 46:2,
place = {United States},
year = 1983,
month = 8
}
  • Free-living soybean rhizobia and Bradyrhizobium spp. (lupine) have the ability to catabolize ethanol. Of the 30 strains of rhizobia examined, only the fast- and slow-growing soybean rhizobia and the slow-growing Bradyrhizobium sp (lupine) were capable of using ethanol as a sole source of carbon and energy for growth. Two strains from each of the other Rhizobium species examined (R. meliloti, R. loti, and R. leguminosarum biovars phaseoli, trifolii, and viceae) failed to grow on ethanol. One Rhizobium fredii (fast-growing) strain, USDA 191, and one (slow-growing) Bradyrhizobium japonicum strain, USDA 110, grew in ethanol up to concentrations of 3.0 and 1.0%,more » respectively. While three of the R. fredii strains examined (USDA 192, USDA 194, and USDA 205) utilized 0.2% acetate, only USDA 192 utilized 0.1% n-propanol. None of the three strains utilized 0.1% methanol, formate, or n-butanol as the sole carbon source.« less
  • Thirty-nine wild-type strains of Rhizobium japonicum have been studied for their ability to synthesize nitrogenase ex planta in defined liquid media under microaerobic conditions. Twenty-one produced more than trace amounts of acetylene reduction activity, but only a few of these yielded high activity. The oxygen response curves were similar for most of the nitrogenase-positive strains. The strains derepressible for activity had several phenotypic characteristics different from non-derepressible strains. These included slower growth and lower oxygen consumption under microaerobic conditions and lower extracellular polysaccharide production. Extracellular polysaccharide production during growth on gluconate in every nitrogenase-positive strain assayed was lower under bothmore » aerobic and microaerobic conditions than the non-depressible strains. These phenotypic characteristics may be representative of a genotype of a subspecies of R. japonicum. These studies were done in part to enlarge the base number of strains available for studies on the physiology, biochemistry, and genetics of nitrogen fixation. (35 Refs.)« less
  • An experiment was conducted to test the hypothesis that, when nitrogenase and nitrate reductase both contribute to the nitrogen nutrition of a nodulated legume, nitrogenase activity is inversely proportional to the rate of accumulation of organic nitrogen derived from the reduction of nitrate. Trifolium subterraneum L. plants, inoculated with Rhizobium trifolii and sown as small swards, were allowed to establish a closed canopy and steady rates of growth, dinitrogen fixation, and nitrogen accumulation. Swards were then supplied with nutrient solutions of 0, 0.5, 1.0, or 2.5 mM NO/sub 3//sup -/ with a 29.69% enrichment of /sup 15/N and allowed tomore » grow for a further 33 days. Harvests were made to measure dry weight, nitrogen accumulation, /sup 15/N accumulation, NO/sub 3//sup -/ content and nitrogenase activity by acetylene reduction assay. Since the /sup 15/N of the plant organic matter could have been derived only from the NO/sub 3//sup -/ of the nutrient solution, its rate of accumulation provided a measure of the rate of NO/sub 3//sup -/ reduction. It was found that as this rate increased in response to external NO/sub 3//sup -/ concentration the rate of nitrogenase activity decreased proportionately. It is concluded that the reduction of nitrate and the reduction of dinitrogen act in a complementary manner to supply a plant with organic nitrogen for growth.« less
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