title: Combined scanning transmission X-ray and electron microscopy for the characterization of bacterial endospores.
abstract: Endospores (also referred to as bacterial spores) are bacterial structures formed by several bacterial species of the phylum Firmicutes. Spores form as a response to environmental stress. These structures exhibit remarkable resistance to harsh environmental conditions such as exposure to heat, desiccation, and chemical oxidants. The spores include several layers of protein and peptidoglycan that surround a core harboring DNA as well as high concentrations of calcium and dipicolinic acid (DPA). A combination of scanning transmission X-ray microscopy, scanning transmission electron microscopy, and energy dispersive spectroscopy was used for the direct quantitative characterization of bacterial spores. The concentration and localization of DPA, Ca(2+) , and other elements were determined and compared for the core and cortex of spores from two distinct genera: Bacillus subtilis and Desulfotomaculum reducens. This micro-spectroscopic approach is uniquely suited for the direct study of individual bacterial spores, while classical molecular and biochemical methods access only bulk characteristics.
authors.affiliation: Institute of Molecular Biology, SAS, Bratislava, Slovakia; Environmental Microbiology Laboratory of ENAC EPFL, Lausanne, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Jamroskovic
authors.forename: Paul P
authors.initials: PP
authors.lastname: Shao
authors.forename: Elena
authors.initials: E
authors.lastname: Suvorova
authors.forename: Imrich
authors.initials: I
authors.lastname: Barak
authors.forename: Rizlan
authors.initials: R
authors.lastname: Bernier-Latmani
mesh_terms: D001412:Bacillus subtilis / Q000737:chemistry / Q000648:ultrastructure; D045859:Desulfotomaculum / Q000737:chemistry / Q000648:ultrastructure; D004577:Electron Probe Microanalysis / Q000379:methods*; D004602:Elements; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D010848:Picolinic Acids / Q000032:analysis; D013171:Spores, Bacterial / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D004602:Elements; D010848:Picolinic Acids; C004860:dipicolinic acid
keywords: Bacillus subtilis; DPA; EDS; STEM; STXM; sporulation