Lam, KP; Hitchcock, AP; Obst, M; Lawrence, JR; Swerhone, GDW; Leppard, GG; Tyliszczak, T; Karunakaran, C; Wang, J; Kaznatcheev, KV; Bazylinski, DA; Lins, U: Characterizing magnetism of individual magnetosomes by X-ray magnetic circular dichroism in a scanning transmission X-ray microscope, Chemical Geology, 270(1-4), 110-116 (2010), online: 22.11.2009, doi:10.1016/j.chemgeo.2009.11.009 [Link]
Abstract:

Soft X-ray scanning transmission X-ray microscopy (STXM) was used to measure the Fe L2, 3 X-ray magnetic circular dichroism (XMCD) signal from individual, 30 nm diameter magnetosomes in a magnetotactic bacterium, specifically the marine vibrio strain MV-1. The Fe L2, 3 spectra recorded with circularly polarized X-rays from an elliptically polarizing undulator were very similar in shape and magnitude to those of fully saturated magnetite (Fe3O4). As previously determined by other techniques, our results show that the magnetic moments of individual magnetosomes arranged in linear chains in intact cells of strain MV-1 are all oriented in the same direction. The magnitude of the XMCD signal averaged over a chain of 9 magnetosomes in one cell is similar to that of single crystal magnetite. The spectral shape is slightly different, and indicates that magnetosomes have excess Fe(II), as noted in previous bulk studies of biogenic magnetite. To our knowledge, this is the first measurement of the XMCD of individual magnetosomes in magnetotactic bacteria.

Aktuelle Termine
Ökologisch-Botanischer Garten:
Mi. 11.08.2021
Führung: "Grüne Apotheke: Heilpflanzen
So. 15.08.2021
Führung: Der ÖGB zum Kennenlernen
So. 05.09.2021
Führung "Lebensraum Wiese: Vielfalt erforschen"
Mi. 08.09.2021
Führung "Erdnuss und Johannisbrot: Tropische Hülsenfrüchte"
Mi. 15.09.2021
Führung "Authentische Einblicke in die Welt der Kaffeebauern - Führung durch die Ausstellung
Wetter Versuchsflächen
Luftdruck (356m): 970.9 hPa
Lufttemperatur: 14.7 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: 2 h/d
Wind (Höhe 17m): 6.0 km/h
Wind (Max.): 14.0 km/h
Windrichtung: SW

...mehr
Globalstrahlung: 27 W/m²
Lufttemperatur: 11.6 °C
Niederschlag: 0.6 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 32m): 0.0 km/h

...mehr
Diese Webseite verwendet Cookies. weitere Informationen