Imaging biomineralizing bacteria in their native-state with X-ray fluorescence microscopy

Area of Science:

• Nanotechnology
• Biomineralization
• Environmental Science

Background:

• Understanding metal-nanoparticle interactions in biological systems is challenging at the nanoscale.
• Observing dynamic processes like metal distribution and nanoparticle growth in native states (in vivo) is difficult.

Purpose of the Study:

• To demonstrate direct measurement of iron content in hydrated, magnetite-biomineralizing magnetotactic bacteria.
• To capture nanoparticle formation dynamics in situ using advanced X-ray techniques.

Main Methods:

• Synchrotron-based nanobeam-scanning X-ray fluorescence microscopy (XFM) with a liquid cell environment.
• X-ray absorption spectroscopy (XAS) for iron chemical speciation analysis.
• Microfluidic device for tracking biomineralization under an X-ray beam.

Main Results:

• Direct measurement of iron content in individual, hydrated magnetotactic bacteria.
• Elemental and chemical speciation information of iron was obtained from bacteria in liquid.
• Successful tracking of magnetite nanoparticle formation over several hours in situ.

Conclusions:

• X-ray fluorescence microscopy in liquid cell setups provides elemental and chemical insights into biological processes at the single-cell level.
• Combining X-ray nanobeam techniques with liquid cell devices enables 'on-chip' experiments for studying metals in biological contexts.
• This approach offers a powerful tool for investigating nanoparticle-biomaterial interactions in complex environments.