Azotobacter vinelandii

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 ... 

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. 

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). 

Three enzymes in Azotobacter vinelandii (Riittimann-Johnson et al. 2003) and Rho-dopseudomonas palustris (Oda et al. 2005) are capable of reducing dinitrogen the nif-encoded enzyme containing molybdenum and iron, the vn/that encodes a vanadium and iron enzyme, and the anf that is an iron-only enzyme. 

Riittimann-Johnson C, LM Rubio, DR Dean, PW Ludden (2003) VnfY is required for full activity of the vanadium-containing dinitrogenase m Azotobacter vinelandii. J Bacterial 185 2383-2386. 

Groseclose EE, DW Ribbons (1981) Metabolism of resorcinolic compounds by bacteria a new pathway for resorcinol catabolism in Azotobacter vinelandii. J Bacteriol 146 460-466. 

Snoep, J.L., de Graef, M.R., Westphal, A.H., de Kok, A., Teixeira, de Mattos, M.J. and Neijssel, O.M. (1993) Differences in sensitivity to NADH of purified pyruvate dehydrogenase complexes of Enterococcus faecalis, Lactococcus lactis, Azotobacter vinelandii and Escherichia colt, implications for their activity in vivo. FEMS Microbiology Letters 114, 279-283. 

Oxygen Azotobacter vinelandii Azobacter beijerinckii Rhizobium 0RS571... 

Such a situation occurs in continuous processes, and can be realized in special cases with cells growing unlimited in discontinuous processes, e. g., as reported in several studies of Alcaligenes latus [60], Azotobacter vinelandii [98], or Methylobacterium rhodesianum [74]. 

Bastiaens, P. I. H., van Hoek, A., Benen, J. A., Brochon, J. C. and Visser, A. J. W. G. (1992). Conformational dynamics and intersubunit energy transfer in wild-type and mutant lipoamide dehydrogenase from Azotobacter vinelandii. A multidimensional time-resolved polarized fluorescence study. Biophys. J. 63, 839-53. 

FIGURE 12.4 S = 7/2 EPR of the [8Fe-7S] P-cluster in Azotobacter vinelandii nitrogenase. The experimental spectrum (trace A) has been simulated in the absence (trace B) and the presence (trace C) of D-strain modeled as a correlated distribution in the zero-field parameters D and E. 

Pierik, A.J., Wassink, H., Haaker, H., and Hagen, W.R. 1993. Redox properties and EPR spectroscopy of the P clusters of Azotobacter vinelandii MoFe protein. European Journal of Biochemistry 212 51-61. 

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