title: Quantitative Imaging of Single Unstained Magnetotactic Bacteria by Coherent X-ray Diffraction Microscopy.
abstract: Novel coherent diffraction microscopy provides a powerful lensless imaging method to obtain a better understanding of the microorganism at the nanoscale. Here we demonstrated quantitative imaging of intact unstained magnetotactic bacteria using coherent X-ray diffraction microscopy combined with an iterative phase retrieval algorithm. Although the signal-to-noise ratio of the X-ray diffraction pattern from single magnetotactic bacterium is weak due to low-scattering ability of biomaterials, an 18.6 nm half-period resolution of reconstructed image was achieved by using a hybrid input-output phase retrieval algorithm. On the basis of the quantitative reconstructed images, the morphology and some intracellular structures, such as nucleoid, polyβ-hydroxybutyrate granules, and magnetosomes, were identified, which were also confirmed by scanning electron microscopy and energy dispersive spectroscopy. With the benefit from the quantifiability of coherent diffraction imaging, for the first time to our knowledge, an average density of magnetotactic bacteria was calculated to be ∼1.19 g/cm(3). This technique has a wide range of applications, especially in quantitative imaging of low-scattering biomaterials and multicomponent materials at nanoscale resolution. Combined with the cryogenic technique or X-ray free electron lasers, the method could image cells in a hydrated condition, which helps to maintain their natural structure.
authors.affiliation: †State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors.forename: Jiadong
authors.initials: J
authors.lastname: Fan
authors.affiliation: †State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Sun
authors.affiliation: †State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: ‡School of Information Science and Engineering, Shandong University, Jinan 250100, China.
authors.forename: Qingjie
authors.initials: Q
authors.lastname: Huang
authors.affiliation: †State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors.forename: Shengkun
authors.initials: S
authors.lastname: Yao
authors.affiliation: †State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors.forename: Yunbing
authors.initials: Y
authors.lastname: Zong
authors.affiliation: §RIKEN SPring-8 Center, 1-1-1, Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kohmura
authors.affiliation: §RIKEN SPring-8 Center, 1-1-1, Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: †State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.affiliation: †State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
authors.forename: Huaidong
authors.initials: H
authors.lastname: Jiang
mesh_terms: D000465:Algorithms; D007091:Image Processing, Computer-Assisted; D042201:Magnetospirillum / Q000737:chemistry* / Q000302:isolation & purification; D008853:Microscopy; D059629:Signal-To-Noise Ratio; D014961:X-Ray Diffraction