|Schmid, G; Zeitvogel, F; Hao, L; Adaktylou, IJ; Eickhoff, M; Obst, M: Submicron-Scale Heterogeneities in Nickel Sorption of Various Cell–Mineral Aggregates Formed by Fe(II)-Oxidizing Bacteria, Environmental Science & Technology, 50(1), 114-125 (2016), online: 20.11.2015, doi:10.1021/acs.est.5b02955 [Link]|
Fe(II)-oxidizing bacteria form biogenic cell–mineral aggregates (CMAs) composed of microbial cells, extracellular organic compounds, and ferric iron minerals. CMAs are capable of immobilizing large quantities of heavy metals, such as nickel, via sorption processes. CMAs play an important role for the fate of heavy metals in the environment, particularly in systems characterized by elevated concentrations of dissolved metals, such as mine drainage or contaminated sediments. We applied scanning transmission (soft) X-ray microscopy (STXM) spectrotomography for detailed 3D chemical mapping of nickel sorbed to CMAs on the submicron scale. We analyzed different CMAs produced by phototrophic or nitrate-reducing microbial Fe(II) oxidation and, in addition, a twisted stalk structure obtained from an environmental biofilm. Nickel showed a heterogeneous distribution and was found to be preferentially sorbed to biogenically precipitated iron minerals such as Fe(III)-(oxyhydr)oxides and, to a minor extent, associated with organic compounds. Some distinct nickel accumulations were identified on the surfaces of CMAs. Additional information obtained from scatter plots and angular distance maps, showing variations in the nickel–iron and nickel–organic carbon ratios, also revealed a general correlation between nickel and iron. Although a high correlation between nickel and iron was observed in 2D maps, 3D maps revealed this to be partly due to projection artifacts. In summary, by combining different approaches for data analysis, we unambiguously showed the heterogeneous sorption behavior of nickel to CMAs.
Physical constraints and biological controls of plant-environment interactions
Presentations W1/W3 Professorship Geoinformatics and Spatial Big Data
Verschoben auf WS 2020/21! Investigating communal pathogen defense and its role in social evolution
|Mi. 01.07.2020 aktuell|
Alle Termine im Juli 2020 entfallen!
|Fr. 03.07.2020 aktuell|
Gewächshäuser ab sofort wieder geöffnet!
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
EGU – interesting research and free coffee