HYDROXYLAMINE AS A SOURCE OF NITROGEN FOR AZOTOBACTER VINELANDII

Hydroxylamine as a Source of Nitrogen for Azotobacter Vinelandii.

Nitrogen Fixation by Azotobacter vinelandii

Nitrogenase was isolated and purified from wildtype and a tungsten-resistant mutant (LM2) of Azotobacter vinelandii strain OP derepressed on medium containing 1-10 mM W. While the enzyme from the wild-type strain contained the polypeptides of the conventional enzyme, metal analysis of component 1 demonstrated the existence of one atom each of molybdenum and tungsten. Furthermore, the ESR spectr...

The Utilization of Nitrogen in Hydroxylamine and Oximes by Azotobacter vinelandii.

Recent studies have provided several types of evidence supporting the view that ammonia is the key intermediate in nitrogen fixation by Azotobacter. An alternative hypothesis based on hydroxylamine depends almost entirely on the detection of traces of oximes in cultures fixing nitrogen. Although the two hypotheses are not mutually exclusive (Burris and Wilson, 1945), hydroxylamine remains an im...

Correlation of ultrastructure in Azotobacter vinelandii with nitrogen source for growth.

Azotobacter synthesizes an extensive internal membranous nework when grown with air (N(2)), i.e., under conditions when these bacteria fix nitrogen. Very slight quantities of internal membrane, concentrated mainly about the cell periphery, are formed when Azotobacter grows with fixed nitrogen, i.e., ammonia and amino acids. Compared to cells growing with ammonia, cells utilizing atmospheric nit...

Evidence for an alternative nitrogen fixation system in Azotobacter vinelandii.

Two Azotobacter vinelandii strains capable of growing on N2(Nif+) were isolated from two different mutant strains that lacked dinitrogenase activity (Nif-). Extracts of N2-grown cells of the two Nif+ strains lacked significant amounts of the "conventional" dinitrogenase protein subunits, as determined by two-dimensional gel electrophoresis. Instead, the extracts contained at least four new prot...