Nitrogen fixing

A number of nitrogen-fixing bacteria contain vanadium and it has been shown that in one of these, Azotobacter, there are three distinct nitrogenase systems based in turn on Mo, V and Fe, each of which has an underlying functional and structural similarity.This discovery has prompted a search for models and the brown compound [Na(thf)]+[V(N2)2(dppe)2] (dppe = Pli2PCH2CH2PPh2) has recently been prepared by reduction of VCI3 by sodium naphthalenide... [Pg.999]

Nitrogen fixation takes place in a wide variety of bacteria, the best known of which is rhizobium which is found in nodules on the roots of leguminous plants such as peas, beans, soya and clover. The essential constituents of this and all other nitrogen-fixing bacteria are ... [Pg.1035]

Ammonium salts or amino adds are by far the most commonly used nitrogen sources in production media. Nitrate is rarely used. Although most nitrogen fixing micro-organisms do produce exopolysaccharide, their growth and the quantity of the... [Pg.202]

Enzyme Formation and Polysaccharide Synthesis by Bacteria. III. Polysaccharides Produced by Nitrogen-fixing Organisms, W. A. Cooper, W. D. Daker, and M. Stacey, Biochem. J., 32 (1938) 1752-1758. [Pg.20]

Trace metals can serve as essential nutrients and as toxic substances (Sunda et al, 1991 Frausto da Silva and Williams, 1991). For example, cobalt is a component of vitamin B-12. This vitamin is essential for nitrogen fixing algae. In contrast, copper is toxic to marine phytoplankton at free ion concentrations similar to those found in seawater (Sunda and... [Pg.250]

As mentioned previously, the fixation-denitrification cycle (Fig. 12-7) is the most heavily perturbed by humans. This is due to both the increasing use of nitrogenous fertilizers and the planting of nitrogen-fixing plants. One of the... [Pg.333]

Metal complexes as inorganic nitrogen-fixing systems Fixation of molecular nitrogen and ammonia synthesis Complexes of dinitrogen... [Pg.518]

Model studies in nitrogen fixation and cobalamin chemistry Nitrogen-fixing plants... [Pg.518]

Treatment of an extracellular polysaccharide of Rhizobium japonicum (an important factor for nitrogen-fixing symbiosis between bacteria and soybeans) with liquid HF (—40°, 30 min) gave mono- and oligo-saccharides involving 0- -D-glucopyranosyl-( 1 - 3)-C>-(4-0-acetyl-a-D-galactopyrano-syluronic acid)-(l— 3)-D-mannose and its 1-fluoride. [Pg.98]

C14-0026. Nitrogen-fixing bacteria react N2 with H2 O to produce NH3 and O2 using ATP as their energy source. About 24 molecules of ATP are consumed per molecule of N2 fixed. What percentage of the free energy derived from ATP is stored in NH3 ... [Pg.1030]

Khammas, K. M., Ageron, E., Grimont, P A D. and Kaiser, P., 1989. Azospirillum irakense sp. nov., a nitrogen-fixing bacterium associated with rice roots and rhizosphere soil. Res. Microbiol. 140, 679-693. [Pg.383]

Reinhold, B., Hurek, T., Fendrik, I., Pot, B., Gillis, M., Kersters, K., Thielemans, S. and De Ley, J. 1987. Azospirillum halopraeferans sp. nov., a nitrogen-fixing organism associated with roots of Kallar grass (Leplochloa fusca (L.) Kunth.). Int. J. Syst. Bacteriol 37 43-51. [Pg.384]

Fallik E, Y-K Chan, RL Robson (1991) Detection of alternative nitrogenases in aerobic gram-negative nitrogen-fixing bacteria. J Bacteriol 173 365-371. [Pg.271]

K. J. Lee and M. H. Gaskins, Increased root exudation of C-compounds by sorghum. seedlings inoculated with nitrogen-fixing bacteria. Plant and Soil 69 391 (1982). [Pg.129]

IV. THE COMPROMISE OF NITROGEN-FIXING SYMBIOSES A NECESSARY TOLL OR A SUPERFLUOUS GOOD ... [Pg.300]

V. WHY HAVE CEREALS NOT YET DEVELOPED TIGHT NITROGEN-FIXING SYMBIOSES ... [Pg.301]

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