Hunter, RC; Hitchcock, AP; Dynes, JJ; Obst, M; Beveridge, TJ: Mapping the Speciation of Iron in Pseudomonas aeruginosa Biofilms Using Scanning Transmission X-ray Microscopy, Environmental Science and Technology, 42(23), 8766-8772 (2008), online: 28.10.2008, doi:10.1021/es801642z [Link] | |
Abstract: An important feature of microbial communities is the spatial heterogeneity of extracellular chemistry. Scanning transmission X-ray microscopy (STXM) was used to map the spatial distribution of iron species throughout Pseudomonas aeruginosa biofilms to assess the influence of chemical heterogeneity on biomineralization. P. aeruginosa biofilms were treated with Fe(III)-amended media. Speciation and quantitative mapping using STXM image sequences in the Fe 2p3/2 (L3) absorption edge region revealed both Fe(II) and Fe(III) in localized microenvironments. Fe(III) was mainly associated with cell surfaces, while small amounts of Fe(II) was found in the extracellular space. Biofilms were also characterized using C 1s edge STXM image sequences. Anaerobic growth assays and confocal microscopy revealed the inability of P. aeruginosa to directly reduce Fe(III), implicating indirect iron reduction mechanisms in the formation of fine-grained, multivalent minerals. These studies suggest that geochemical microenvironments found throughout microbial communities are even more complex than previously believed. |
BayCEER Short Courses: |
---|
Fr. 26.04.2024 aktuell Mobile Film Making Workshop (for students of BayCEER) |
Ökologisch-Botanischer Garten: |
Fr. 26.04.2024 aktuell Aktion | Kräuterreich & regional: Backkunst im ÖBG (zus. mit HWK) |
Fr. 26.04.2024 aktuell Führung | Erdbeer-Minze und Zimmerknoblauch: Gewürzkräuter |
So. 28.04.2024 Führung | Den Sängern auf der Spur: Vogelstimmen im ÖBG (zus. mit LBV) |
So. 05.05.2024 Führung | Faszination Englische Gärten: Gestaltung und Pflanzen |