Imaging Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron Microscopy
Microbe-mineral and -metal interactions represent a major intersection between the biosphere and geosphere but require high-resolution imaging and analytical tools for investigating microscale associations. Electron microscopy has been used extensively for geomicrobial investigations and although used bona fide, the traditional methods of sample preparation do not preserve the native morphology of microbiological components, especially extracellular polymers. Herein, we present a direct comparative analysis of microbial interactions using conventional electron microscopy approaches of imaging at room temperature and a suite of cryo-electron microscopy methods providing imaging in the close-to-natural hydrated state. In situ, we observed an irreversible transformation of bacterial extracellular polymers during the traditional dehydration-based sample preparation that resulted in the collapse of hydrated gel-like EPS into filamentous structures. Dehydration-induced polymer collapse can lead to inaccurate spatial relationships and hence could subsequently affect conclusions regarding nature of interactions between microbial extracellular polymers and their environment.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1009304
- Report Number(s):
- PNNL-SA-73983; 26191; KP1704020
- Journal Information:
- Applied and Environmental Microbiology, 77(4):1254-1262, Journal Name: Applied and Environmental Microbiology, 77(4):1254-1262 Journal Issue: 4 Vol. 77; ISSN AEMIDF; ISSN 0099-2240
- Country of Publication:
- United States
- Language:
- English
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