Complex formation between Azotobacter vinelandii flavodoxin and horse cytochrome c has been demonstrated through cross-linking studies with dimethyl suberimidate, dimethyl adipimidate, 1-ethyl-3-(3-di-methylaminopropyl)carbodiimide, and dimethyl-3,3'-dithiobispropionimidate. Essentially quantitative cross-linking of cytochrome c and flavodoxin was observed at low ionic strengths with the carbod...

Investigations with the isotopic tracer N16 have furnished definite evidence that ammonia is the key intermediate in nitrogen fixation by Azotobacter vinelundii (1). Direct isolation of the intermediate, however, has not been possible, apparently because ammonia is used so rapidly by this bacterium that it does not accumulate. In a study of the comparative biochemistry of nitrogen fixation, we ...

Growth and utilization of different phenolic acids present in olive mill wastewater (OMW) by Azotobacter chroococcum were studied in chemically defined media. Growth and utilization of phenolic acids were only detected when the microorganism was cultured on p-hydroxybenzoic acid at concentration from 0.01% to 0.5% (w/v) and protocatechuic acid at concentration from 0.01% to 0.3% (w/v) as sole c...

Azotobacter vinelandii ferredoxin I is a small protein that contains one [4Fe-4S] cluster and one [3Fe-4S] cluster. Recently the x-ray crystal structure has been redetermined and the fdxA gene, which encodes the protein, has been cloned and sequenced. Here we report the site-directed mutation of Cys-20, which is a ligand of the [4Fe-4S] cluster in the native protein, to alanine and the characte...

Strains of Azotobacter vinelandii which contain defined deletions within the nifD and nifK genes which encode, respectively, the alpha and beta subunits of the MoFe protein of nitrogenase were analyzed. When synthesized without its partner, the beta subunit accumulated as a soluble beta 4 tetramer. In contrast, when the alpha subunit was present without its partner, it accumulated primarily as ...

The aim of this research was to investigate the effect of inoculation (Azotobacter chroococcum and actinomycetes) and nitrogen mineral fertilizers (doses of 60 kg N ha-1 and 120 kg N ha-1) on the yield of wheat and on the number and activity of certain microorganisms in rhizospheric soil. The investigation was carried out in humogley soil with three wheat varieties. The variants of the experime...

The flavoprotein from Azotobacter, first isolated by SHETHNA et al. 1, is chemically well characterized, but its enzymatic function is still obscure. ARNON and coworkers 2 found this flavoprotein to be active in substituting for ferredoxin in the reduction of acetylene by a cell-free nitrogenase preparation from Azotobacter. We have recently confirmed their observation3. In addition, we could d...

Large amounts of homopolymers containing -hydroxybutyrate (PHB) and copolymers containing -hydroxyvalerate (P[HB-co-HV]) are produced by Azotobacter chroococcum strain H23 when growing in culture media amended with alpechı́n (wastewater from olive oil mills) as the sole carbon source. Copolymer was formed when valerate (pentanoate) was added as a precursor to the alpechı́n medium, but it was not ...

Stevenson, L. H. (Louisiana State University, Baton Rouge), and M. D. Socolofsky. Cyst formation and poly-beta-hydroxybutyric acid accumulation in Azotobacter. J. Bacteriol. 91:304-310. 1966.-The relationship between cyst formation and the accumulation of poly-beta-hydroxybutyric acid (PHB) in Azotobacter vinelandii (A. agilis) was investigated. After various periods of growth, the cells were h...

Inoculation of azotobacter has significant positive effects on the growth characteristics and pigments in mangrove seedlings of Avicennia marina and Ceriops decandra. The bacterial inoculation significantly increased the root dry biomass at the maximum of 75.8% at 30 gl(-1) salinity in Ceriops decandra. But in Avicennia marina, the shoot dry biomass was increased significantly at the maximum of...