Evidence for ferritin as dominant iron-bearing species in the rhizobacterium Azospirillum brasilense Sp7 provided by low-temperature/in-field Mössbauer spectroscopy

Krisztina Kovács, Alexander A. Kamnev, Jiří Pechoušek, Anna V. Tugarova, E. Kuzmann, Libor Machala, Radek Zbořil, Z. Homonnay, K. Lázár

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

For the ubiquitous diazotrophic rhizobacterium Azospirillum brasilense, which has been attracting the attention of researchers worldwide for the last 35 years owing to its significant agrobiotechnological and phytostimulating potential, the data on iron acquisition and its chemical speciation in cells are scarce. In this work, for the first time for azospirilla, low-temperature (at 80 K, 5 K, as well as at 2 K without and with an external magnetic field of 5 T) transmission Mössbauer spectroscopic studies were performed for lyophilised biomass of A. brasilense (wild-type strain Sp7 grown with 57FeIII nitrilotriacetate complex as the sole source of iron) to enable quantitative chemical speciation analysis of the intracellular iron. In the Mössbauer spectrum at 80 K, a broadened quadrupole doublet of high-spin iron(III) was observed with a few percent of a high-spin iron(II) contribution. In the spectrum measured at 5 K, a dominant magnetically split component appeared with the parameters typical of ferritin species from other bacteria, together with a quadrupole doublet of a superparamagnetic iron(III) component and a similarly small contribution from the high-spin iron(II) component. The Mössbauer spectra recorded at 2 K (with or without a 5 T external field) confirmed the assignment of ferritin species. About 20 % of total Fe in the dry cells of A. brasilense strain Sp7 were present in iron(III) forms superparamagnetic at both 5 and 2 K, i.e. either different from ferritin cores or as ferritin components with very small particle sizes. [Figure not available: see fulltext.]

Original languageEnglish
Pages (from-to)1-7
Number of pages7
JournalAnalytical and Bioanalytical Chemistry
DOIs
Publication statusAccepted/In press - Jan 14 2016

Fingerprint

Bearings (structural)
Azospirillum brasilense
Ferritins
Spectrum Analysis
Iron
Spectroscopy
Temperature
Chemical speciation
Azospirillum
Magnetic Fields
Particle Size
Biomass
Bacteria
Particle size
Research Personnel
Magnetic fields

Keywords

  • Fe transmission Mössbauer spectroscopy
  • Azospirillum brasilense
  • Bacterial ferritin
  • Iron metabolism

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry

Cite this

Evidence for ferritin as dominant iron-bearing species in the rhizobacterium Azospirillum brasilense Sp7 provided by low-temperature/in-field Mössbauer spectroscopy. / Kovács, Krisztina; Kamnev, Alexander A.; Pechoušek, Jiří; Tugarova, Anna V.; Kuzmann, E.; Machala, Libor; Zbořil, Radek; Homonnay, Z.; Lázár, K.

In: Analytical and Bioanalytical Chemistry, 14.01.2016, p. 1-7.

Research output: Contribution to journalArticle

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abstract = "For the ubiquitous diazotrophic rhizobacterium Azospirillum brasilense, which has been attracting the attention of researchers worldwide for the last 35 years owing to its significant agrobiotechnological and phytostimulating potential, the data on iron acquisition and its chemical speciation in cells are scarce. In this work, for the first time for azospirilla, low-temperature (at 80 K, 5 K, as well as at 2 K without and with an external magnetic field of 5 T) transmission M{\"o}ssbauer spectroscopic studies were performed for lyophilised biomass of A. brasilense (wild-type strain Sp7 grown with 57FeIII nitrilotriacetate complex as the sole source of iron) to enable quantitative chemical speciation analysis of the intracellular iron. In the M{\"o}ssbauer spectrum at 80 K, a broadened quadrupole doublet of high-spin iron(III) was observed with a few percent of a high-spin iron(II) contribution. In the spectrum measured at 5 K, a dominant magnetically split component appeared with the parameters typical of ferritin species from other bacteria, together with a quadrupole doublet of a superparamagnetic iron(III) component and a similarly small contribution from the high-spin iron(II) component. The M{\"o}ssbauer spectra recorded at 2 K (with or without a 5 T external field) confirmed the assignment of ferritin species. About 20 {\%} of total Fe in the dry cells of A. brasilense strain Sp7 were present in iron(III) forms superparamagnetic at both 5 and 2 K, i.e. either different from ferritin cores or as ferritin components with very small particle sizes. [Figure not available: see fulltext.]",
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T1 - Evidence for ferritin as dominant iron-bearing species in the rhizobacterium Azospirillum brasilense Sp7 provided by low-temperature/in-field Mössbauer spectroscopy

AU - Kovács, Krisztina

AU - Kamnev, Alexander A.

AU - Pechoušek, Jiří

AU - Tugarova, Anna V.

AU - Kuzmann, E.

AU - Machala, Libor

AU - Zbořil, Radek

AU - Homonnay, Z.

AU - Lázár, K.

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AB - For the ubiquitous diazotrophic rhizobacterium Azospirillum brasilense, which has been attracting the attention of researchers worldwide for the last 35 years owing to its significant agrobiotechnological and phytostimulating potential, the data on iron acquisition and its chemical speciation in cells are scarce. In this work, for the first time for azospirilla, low-temperature (at 80 K, 5 K, as well as at 2 K without and with an external magnetic field of 5 T) transmission Mössbauer spectroscopic studies were performed for lyophilised biomass of A. brasilense (wild-type strain Sp7 grown with 57FeIII nitrilotriacetate complex as the sole source of iron) to enable quantitative chemical speciation analysis of the intracellular iron. In the Mössbauer spectrum at 80 K, a broadened quadrupole doublet of high-spin iron(III) was observed with a few percent of a high-spin iron(II) contribution. In the spectrum measured at 5 K, a dominant magnetically split component appeared with the parameters typical of ferritin species from other bacteria, together with a quadrupole doublet of a superparamagnetic iron(III) component and a similarly small contribution from the high-spin iron(II) component. The Mössbauer spectra recorded at 2 K (with or without a 5 T external field) confirmed the assignment of ferritin species. About 20 % of total Fe in the dry cells of A. brasilense strain Sp7 were present in iron(III) forms superparamagnetic at both 5 and 2 K, i.e. either different from ferritin cores or as ferritin components with very small particle sizes. [Figure not available: see fulltext.]

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