Mössbauer parameters at 125K for both the oxidized and semi-reduced states of FeMoco isolated from the MoFe protein of Azotobacter vinelandii nitrogenase of delta/Fe = 0.32 and 0.37 mm/s and delta Eq = 0.84 and 0.71 mm/s, respectively, are reported. FeMoco(ox) fits the Debye model perfectly from 4.2-125K and has a S = 0 ground state. FeMoco(ox) apparently contains 10-20% FeMoco(s-r) and vice ve...

The gene encoding the noncoupled NADH:ubiquinone oxidoreductase (NDH II) from Azotobacter vinelandii was cloned, sequenced, and used to construct an NDH II-deficient mutant strain. Compared to the wild type, this strain showed a marked decrease in respiratory activity. It was unable to grow diazotrophically at high aeration, while it was fully capable of growth at low aeration or in the presenc...

Poly-(3-hydroxybutyrate) [P(3HB)] is a polyester synthesized as a carbon and energy reserve material by a wide number of bacteria. This polymer is characterized by its thermo-plastic properties similar to plastics derived from petrochemical industry, such as polyethylene and polypropylene. Furthermore, P(3HB) is an inert, biocompatible and biodegradable material which has been proposed for seve...

Upon encystment induction, Azotobacter vinelandii produces the phenolic lipids alkylresorcinols (ARs) that are structural components of the cysts. The enzymes responsible for the ARs synthesis are encoded in the arsABCD operon, whose expression is activated by ArpR. The transcription of arpR is initiated from an RpoS dependent promoter. The nitrogen-related phosphotransferase system (PTS(Ntr)) ...

Bacterial Nitrogenase, Nitrite Inhibition, Dinitrogenase Reductase Dinitrogen fixation by crude extracts from Rhodopseudomonas palustris and Rhodomicrobium vannielii and by purified nitrogenase preparations from Azotobacter vinelandii and Clostridium pasteurianum is inhibited by nitrite, whereas in the same preparations nitrate is without effect. In Clostridium nitrite seems to interact with di...

Bacterial ferritin from Azotobacter vinelandii (AvBFJ has a function in H2 uptake. The Fe3+ reduction on the surface of the iron core from AvBF0 is accompanied simultaneously by H2 uptake, with a maximum activity of H2 uptake of 450 H2/AvBF0. A reduction potential of -402 mV for iron reduction on the surface of the core is found. A shift to the red the protein absorbance peaks ranging from 280 ...

To evaluate the role of uridylyl-transferase, the Sinorhizobium meliloti glnD gene was isolated by heterologous complementation in Azotobacter vinelandii. The glnD gene is cotranscribed with a gene homologous to Salmonella mviN. glnD1::Omega or mviN1::Omega mutants could not be isolated by a powerful sucrose counterselection procedure unless a complementing cosmid was provided, indicating that ...

The catalysis of nitrogen reduction by extracts of nitrogen-fixing organisms requires an ATPgenerating system and a source of electrons (1, 2, 5, 11, 13). The phosplhoroclastic reaction provides botlh ATP anid electrons for the reduction of nitrogen by cell-free extracts of Clostridium1t pasteurianumn (2, 5, 13) and ferredoxin functions as the natural electron carrier from the phlosphoroclastic...

Stable strains of mutants of Azotobacter that do not fix nitrogen are difficult to obtain by traditional procedures (Karlsson and Barker, 1948; Lindstrom, 1948). Stumbo and Gainey (1938) demonstrated that culturing Azotobacter on a high nitrate medium resulted in strains that failed to fix nitrogen even after continued transfer in the absence of fixed nitrogen. However, since these strains were...

The alginate biofilm-producing bacterium Azotobacter vinelandii aerobically fixes nitrogen by oxygen-sensitive nitrogenases. Here we investigated the bacterial response to nitrogen/oxygen gas mixtures. A. vinelandii cells were cultured in nitrogen-free minimal media containing gas mixtures differing in their ratios of nitrogen and oxygen. The bacteria did not grow at oxygen concentrations >75% ...