Quantitative three-dimensional nondestructive imaging of whole anaerobic ammonium-oxidizing bacteria

Abstract

Anaerobic ammonium-oxidizing (anammox) bacteria play a key role in the global nitrogen cycle and in nitrogenous wastewater treatment. The anammox bacteria ultrastructure is unique and distinctly different from that of other prokaryotic cells. The morphological structure of an organism is related to its function; however, research on the ultrastructure of intact anammox bacteria is lacking. In this study, in situ three-dimensional nondestructive ultrastructure imaging of a whole anammox cell was performed using synchrotron soft X-ray tomography (SXT) and the total variation-based simultaneous algebraic reconstruction technique (TV-SART). Statistical and quantitative analyses of the intact anammox bacteria were performed. High soft X-ray absorption composition inside anammoxosome was detected and verified to be relevant to iron-binding protein. On this basis, the shape adaptation of the anammox bacteria response to iron was explored.

Chameleon-like Anammox Bacteria for Surface Color Change after Suffering Starvation

“…6 During the initial starvation, bacteria often activate regulators such as cAMP, 7 PHO, 8 and (p)ppGpp 9 to enhance tolerance. Long-term starvation induces changes in bacterial morphology, 10 energy distribution, 11 and protein structure adaptation. 12 Under adverse conditions, such as suffering heavy metals, antibiotics, and starvation, the color of activated sludge turns black, which is usually accompanied by deterioration of treatment or even death of bacteria.…”

“…During the initial starvation, bacteria often activate regulators such as cAMP, PHO, and (p)­ppGpp to enhance tolerance. Long-term starvation induces changes in bacterial morphology, energy distribution, and protein structure adaptation …”

Development of a direct-mapping tomography method to solve confined space problems with enhanced calculation efficiency

“…In open-space problems, all light signals emitted by the target (e.g., ames and ows) signal eld are unhindered and can approach the image sensors (e.g., CCD, CMOS cameras and ber-bundle endoscopes), such as measurements on laboratory burners [7][8][9], jet nozzles [10], surface ow [11] and so on. The tomography technology and mathematical inversion algorithms for open space have been widely used and developed in ow and combustion diagnostics [17][18][19][20][21][22][23]. In contrast, the target signal eld of con ned-space problems is typically surrounded by facility walls, which are usually made up of transparent materials (e.g., quartz and sapphire) to provide the optical access.…”