Azotobacter

In Azotobacter, the main enzyme of PolyP metabolism was shown to be polyphosphate kinase (Zaitseva and Belozersky, 1958,1960), which was capable of PolyP synthesis and of a reverse reaction. This enzyme was isolated and purified to a considerable extent (Zaitseva and Belozersky, 1960). 

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Azosprillum Azo-stilbene dyes Azotobacter Azotobacter agilis Azotobacter paspali Azoxy... 

B Shen, DR Jollie, CD Stout, TC Diller, EA Armstrong, CM Gorst, GN La Mar, PJ Stephens, BK Burgess. Azotobacter vmelandii ferredoxm I Alteration of individual surface charges and the [4Ee-4S] cluster reduction potential. 1 Biol Chem 269 8564-8575, 1994. 

J Soman, S Iismaa, CD Stout. Crystallographic analysis of two site-directed mutants of Azotobacter vmelandii feiredoxin. J Biol Chem 266 21558-21562, 1991. 

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... 

A strain of Azotobacter vinelandii was cultured in a 15 m3 stirred fermenter for the production of alginate. Under current conditions the mass transfer coefficient, kLa, is 0.18 s. Oxygen solubility in the fermentation broth is approximately 8 X 10 3 kgm-3.9 The specific oxygen uptake rate is 12.5 mmol g 1 h. What is the maximum cell density in the broth If copper sulphate is accidentally added to the fermentation broth, which may reduce the oxygen uptake rate to 3 mmol g 1 h 1 and inhibit the microbial cell growth, what would be the maximum cell density in this condition ... 

Immunopolysaccharides. Part I, Preliminary Studies of a Polysaccharide from Azotobacter chroococcum, containing a Uronic Acid, G. J. Lawson and M. Stacey, J. Chem. Soc., (1954) 1925-1931. 

Nitrogen Nitrogen fixation [N2 - -> RNH2 some amino Free living prokaryotes Azotobacter (organic... 

Similarly, Ikehara, Tazawa, and Fukui (51) have found that the nucleotides 8-bromo and 8-oxoadenosine 5 -diphosphate, 8-bromo-, 8-oxo, and 8-dimethylaminoguanosine 5 -diphosphate are all inactive as substrates for homopolymer synthesis catalyzed by polynucleotide phosphorylase from Escherichia coli. Some of the results were later confirmed by Kapuler, Monny, and Michelson (52), who found that neither 8-bromo- nor 8-oxoguanosine 5 -diphosphate was active as a substrate for homopolymerization with polynucleotide phosphorylases isolated both irom Azotobacter vinelandii and . coli. 

Petrovskii, A., Loiko, N., Nikolaev, Yu., Kozlova, A., El -Registan, G., Deryabin, D., Mikhailenko, N., Kobzeva, T., Kanaev, P., Krupyanskii, Yu. Regulation of the function activity of lysozyme by alkylhydroxybenzenes. Microbiology, Vol.78, No.2, (March 2009), pp. 144-153, ISSN 1350-0872 Reusch, R., Sadoff, H. Novel lipid components of the Azotobacter vinelandii cyst membrane. 

On the basis of primary sequence considerations, 7Fe Fds can be subdivided into at least two major classes. The first class (Azotobacter-type) is typified by the structurally characterized A. vinelandii Fdl (18, 69, 123, 124) and has two groups of coordinating cysteine residues with consensus sequences of -C-X2-X-K-X3-C-Xg-g-P-V- and -g-Xs-C-Xs-Q-Xg-C-P- for the first and second groupings, respectively. The C and C residues ligate the [FegS4] and [Fe4S4l clusters, respectively, and the X residue is C, V, T, or E see Table II. In addition to the anomalous arrangement of cysteine resi-... 

In late 1992 the first crystal structures of the Fe and MoFe proteins of Mo nitrogenase frora Azotobacter vinelandii were published (1-3). 

Fig. 2. The structure of the Fe protein (Av2) from Azotobacter vinelandii, after Geor-giadis et al. (1). The dimeric polypeptide is depicted by a ribbon diagram and the Fe4S4 cluster and ADP by space-filling models (MOLSCRIPT (196)). The Fe4S4 cluster is at the top of the molecule, bound equally to the two identical subunits, Emd the ADP molecule spans the interface between the subunits with MoO apparently binding in place of the terminal phosphate of ATP.

The nitrogenase proteins are generally characterized by two letters indicating the species and strains of bacteria and the numerals 1 for the MoFe protein and 2 for the Fe protein. Thus, the Fe protein from Azotobacter vinelandii is Av2 and the MoFe protein from Klebsiella pneumoniae is Kpl. 

Fig. 12. The nitrogen fixation genes of Azotobacter vinelandii. This orgEinism has three nitrogenase systems, viz nif, vnf, and anf, which it uses for fixing N2 under different environmental conditions. The boxes with slanted hatching indicate the structural genes of the three systems, those colored dark gray are required for eiU three systems, and those with vertical hatching are required for both the vnf and anf systems.

Although, as indicated in Fig. 12, there is clear genetic evidence for a third nitrogenase in Azotobacter vinelandii, the initial preparations of this enzyme had low activity and contained small quantities of molybdenum as well as iron, and thus the activity might have been... 

A relationship between the redox state of an iron—sulfur center and the conformation of the host protein was furthermore established in an X-ray crystal study on center P in Azotobacter vinelandii nitroge-nase (270). In this enzyme, the two-electron oxidation of center P was found to be accompanied by a significant displacement of about 1 A of two iron atoms. In both cases, this displacement was associated with an additional ligation provided by a serine residue and the amide nitrogen of a cysteine residue, respectively. Since these two residues are protonable, it has been suggested that this structural change might help to synchronize the transfer of electrons and protons to the Fe-Mo cofactor of the enzyme (270). 

Azotobacters. Burk and Winogradsky in the 1930s showed that these could readily be obtained from soil samples by elective enrichment with benzoate. The degradative pathway for benzoate has been elucidated (Hardisson et al. 1969), and the range of substrates extended to 2,4,6-trichlorophenol (Li et al. 1992 Latus et al. 1995). The enzyme from Azotobacter sp. strain GPl that catalyzes the formation of 2,6-dichlorohydroquinone from... 

Hardisson C, JM Sala-Trapat, RY Stanier (1969) Pathways for the oxidation of aromatic compounds by Azotobacter. J Gen Microbiol 59 1-11. 

Latus M, H-J Seitz, J Eberspacher, E Lingens (1995) Purification and characterization of hydroxyquinol 1,2-dioxygenase from Azotobacter sp. strain GPl. Appl Environ Microbiol 61 2453-2460. 

Wieser M, B Wagner, J Eberspacher, F Lingens (1997) Puriflcation and characterization of 2,4,6-trichloro-phenol-4-monooxygenase, a dehalogenating enzyme imm Azotobacter sp. strain GPL J Bacterial 179 202-208. 

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