Abstract
The free-living diazotroph Azotobacter chroococcum B-8 responded to iron-limited growth conditions by forming hydroxamic acids and an 85,000-dalton outer membrane protein. The Fe(III)-binding hydroxamate compounds stimulated the growth of Arthrobacter flavescens JG-9 and gave a positive Csaky reaction for bound hydroxylamines. The hydroxamates were isolated from liquid cultures by benzyl alcohol extraction and purified by size exclusion chromatography and high-performance liquid chromatography. Four high-performance liquid chromatography fractions, designated A, B, C, and D, had the characteristic hydroxamate absorption maximum at 420 to 423 nm, which did not shift over a pH range from 3.0 to 9.0. Cyclic voltammograms of the iron-hydroxamate complexes exhibited reduction potentials of −0.426 to −0.442 V for fractions A, B, and D and of −0.56 V for fraction C versus the normal hydrogen electrode at pH 8.0. Based on mass spectra, nominal molecular weights of 800 and 844 were assigned to ferrated compounds A and B, respectively. Reductive hydrolysis of compounds A and B in 57% hydriodic acid yielded ornithine as detected by gas chromatography-mass spectrometry. All of these physiological and chemical data strongly support the hypothesis that the high-affinity iron-binding compounds isolated from A. chroococcum B-8 are hydroxamic acids and probably function as siderophores for this diazotroph.
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- Atkin C. L., Neilands J. B. Rhodotorulic acid, a diketopiperazine dihydroxamic acid with growth-factor activity. I. Isolation and characterization. Biochemistry. 1968 Oct;7(10):3734–3739. doi: 10.1021/bi00850a054. [DOI] [PubMed] [Google Scholar]
- BULEN W. A., LECOMTE J. R. Isolation and properties of a yellow-green fluorescent peptide from azotobacter medium. Biochem Biophys Res Commun. 1962 Dec 19;9:523–528. doi: 10.1016/0006-291x(62)90119-5. [DOI] [PubMed] [Google Scholar]
- BURNHAM B. F., NEILANDS J. B. Studies on the metabolic function of the ferrichrome compounds. J Biol Chem. 1961 Feb;236:554–559. [PubMed] [Google Scholar]
- Brill W. J. Biochemical genetics of nitrogen fixation. Microbiol Rev. 1980 Sep;44(3):449–467. doi: 10.1128/mr.44.3.449-467.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Byers B. R., Powell M. V., Lankford C. E. Iron-chelating hydroxamic acid (schizokinen) active in initiation of cell division in Bacillus megaterium. J Bacteriol. 1967 Jan;93(1):286–294. doi: 10.1128/jb.93.1.286-294.1967. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Corbin J. L., Bulen W. A. The isolation and identification of 2,3-dihydroxybenzoic acid and 2-N,6-N-di-92,3-dihydroxybenzoyl)-L-lysine formed by iron-deficient Azotobacter vinelandii. Biochemistry. 1969 Mar;8(3):757–762. doi: 10.1021/bi00831a002. [DOI] [PubMed] [Google Scholar]
- Darbre A., Islam A. Gas-liquid chromatography of trifluoroacetylated amino acid methyl esters. Biochem J. 1968 Feb;106(4):923–925. doi: 10.1042/bj1060923. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Emery T. Malonichrome, a new iron chelate from Fusarium roseum. Biochim Biophys Acta. 1980 May 7;629(2):382–390. doi: 10.1016/0304-4165(80)90110-5. [DOI] [PubMed] [Google Scholar]
- Fekete F. A., Spence J. T., Emery T. A rapid and sensitive paper electrophoresis assay for the detection of microbial siderophores elicited in solid-plating culture. Anal Biochem. 1983 Jun;131(2):516–519. doi: 10.1016/0003-2697(83)90207-5. [DOI] [PubMed] [Google Scholar]
- Fekete F. A., Spence J. T., Emery T. Siderophores Produced by Nitrogen-Fixing Azotobacter vinelandii OP in Iron-Limited Continuous Culture. Appl Environ Microbiol. 1983 Dec;46(6):1297–1300. doi: 10.1128/aem.46.6.1297-1300.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gibson F., Magrath D. I. The isolation and characterization of a hydroxamic acid (aerobactin) formed by Aerobacter aerogenes 62-I. Biochim Biophys Acta. 1969 Nov 18;192(2):175–184. doi: 10.1016/0304-4165(69)90353-5. [DOI] [PubMed] [Google Scholar]
- Knosp O., von Tigerstrom M., Page W. J. Siderophore-mediated uptake of iron in Azotobacter vinelandii. J Bacteriol. 1984 Jul;159(1):341–347. doi: 10.1128/jb.159.1.341-347.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Neilands J. B. Microbial iron compounds. Annu Rev Biochem. 1981;50:715–731. doi: 10.1146/annurev.bi.50.070181.003435. [DOI] [PubMed] [Google Scholar]
- Page W. J. Iron-Dependent Production of Hydroxamate by Sodium-Dependent Azotobacter chroococcum. Appl Environ Microbiol. 1987 Jul;53(7):1418–1424. doi: 10.1128/aem.53.7.1418-1424.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Page W. J., von Tigerstrom M. Iron- and molybdenum-repressible outer membrane proteins in competent Azotobacter vinelandii. J Bacteriol. 1982 Jul;151(1):237–242. doi: 10.1128/jb.151.1.237-242.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robson R. L., Postgate J. R. Oxygen and hydrogen in biological nitrogen fixation. Annu Rev Microbiol. 1980;34:183–207. doi: 10.1146/annurev.mi.34.100180.001151. [DOI] [PubMed] [Google Scholar]
- Schwyn B., Neilands J. B. Universal chemical assay for the detection and determination of siderophores. Anal Biochem. 1987 Jan;160(1):47–56. doi: 10.1016/0003-2697(87)90612-9. [DOI] [PubMed] [Google Scholar]
- Shah V. K., Davis L. C., Brill W. J. Nitrogenase. I. Repression and derepression of the iron-molybdenum and iron proteins of nitrogenase in Azotobacter vinelandii. Biochim Biophys Acta. 1972 Feb 28;256(2):498–511. doi: 10.1016/0005-2728(72)90078-3. [DOI] [PubMed] [Google Scholar]