title: X-ray microtomographic visualization of Escherichia coli by metalloprotein overexpression.
abstract: This paper reports X-ray microtomographic visualization of the microorganism Escherichia coli overexpressing a metalloprotein ferritin. The three-dimensional distribution of linear absorption coefficients determined using a synchrotron radiation microtomograph with a simple projection geometry revealed that the X-ray absorption was homogeneously distributed, suggesting that every E. coli cell was labeled with the ferritin. The ferritin-expressing E. coli exhibited linear absorption coefficients comparable with those of phosphotungstic acid stained cells. The submicrometer structure of the ferritin-expressing E. coli cells was visualized by Zernike phase contrast using an imaging microtomograph equipped with a Fresnel zone plate. The obtained images revealed curved columnar or bunching oval structures corresponding to the E. coli cells. These results indicate that the metalloprotein overexpression facilitates X-ray visualization of three-dimensional cellular structures of biological objects.
authors.affiliation: Graduate School of Engineering, Tokai University, Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan. ryuta@tokai-u.jp
authors.forename: Ryuta
authors.initials: R
authors.lastname: Mizutani
authors.forename: Keisuke
authors.initials: K
authors.lastname: Taguchi
authors.forename: Masato
authors.initials: M
authors.lastname: Ohtsuka
authors.forename: Minoru
authors.initials: M
authors.lastname: Kimura
authors.forename: Akihisa
authors.initials: A
authors.lastname: Takeuchi
authors.forename: Kentaro
authors.initials: K
authors.lastname: Uesugi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Suzuki
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers; D004577:Electron Probe Microanalysis; D004926:Escherichia coli / Q000378:metabolism*; D008667:Metalloproteins / Q000378:metabolism*; D055114:X-Ray Microtomography
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D008667:Metalloproteins
keywords: bacteria; ferritin; high-Z element; micro-CT; three-dimensional structure