|Schmid, G; Zeitvogel, F; Hao, L; Ingino, P; Kuerner, W; Dynes, JJ; Karunakaran, C; Wang, J; Lu, Y; Ayers, T; Schietinger, C; Hitchcock, AP; Obst, M: Synchrotron-Based Chemical Nano-Tomography of Microbial Cell-Mineral Aggregates in their Natural, Hydrated State, Microscopy and Microanalysis, 20(2), 531-536 (2014), online: 2014-02-19, doi:10.1017/S1431927613014104 [Link]|
Chemical nano-tomography of microbial cells in their natural, hydrated state provides direct evidence of metabolic and chemical processes. Cells of the nitrate-reducing Acidovorax sp. strain BoFeN1 were cultured in the presence of ferrous iron. Bacterial reduction of nitrate causes precipitation of Fe(III)-(oxyhydr)oxides in the periplasm and in direct vicinity of the cells. Nanoliter aliquots of cell-suspension were injected into custom- designed sample holders wherein polyimide membranes collapse around the cells by capillary forces. The immobilized, hydrated cells were analyzed by synchrotron-based scanning transmission X-ray microscopy in combination with angle-scan tomography. This approach provides three-dimensional (3D) maps of the chemical species in the sample by employing their intrinsic near-edge X-ray absorption properties. The cells were scanned through the focus of a monochromatic soft X-ray beam at different, chemically specific X-ray energies to acquire projection images of their corresponding X-ray absorbance. Based on these images, chemical composition maps were then calculated. Acquiring projections at different tilt angles allowed for 3D reconstruction of the chemical composition. Our approach allows for 3D chemical mapping of hydrated samples and thus provides direct evidence for the localization of metabolic and chemical processes in situ.
|Fr. 2020-07-10 now|
12th BayCEER Workshop 2020: "Call for Abstracts" is open
Extreme redox oscillations in freshwater re-flooded acid sulfate soil wetlands: Effects on Fe, S, and trace metals geochemical behavior
Dissolved organic matter quality in differently managed forest ecosystems
Signaling of rhizosphere microbiome: key for plant health, development and nutrition
BayCEER Workshop 2020
Why Science Communication?
Stoichiometric controls of C and N cycling
Flying halfway across the globe to dig in the dirt – a research stay in Bloomington, USA
Picky carnivorous plants?