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Desiccation tolerance of prokaryotes
1Department of Biochemistry and Anaerobic Microbiology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
Microbiological Reviews
|December 1, 1994
Summary
Prokaryotic cells survive extreme dehydration through complex molecular and structural adaptations, differing from responses to osmotic stress. Understanding bacterial desiccation tolerance is crucial for various applications.
Area of Science:
- Microbiology
- Evolutionary Biology
- Biochemistry
Background:
- Cell-bound water removal and rehydration are key evolutionary forces for prokaryotes.
- Bacterial cells exhibit varying survival times under desiccation, from seconds to millennia.
- Desiccated cells have minimal water content, disrupting macromolecular integrity.
Purpose of the Study:
- To review the knowns and unknowns of desiccation tolerance in prokaryotic cells.
- To differentiate desiccation tolerance mechanisms from those for osmotic or freeze-thaw stress.
- To explore the role of water molecule properties in cellular stability.
Main Methods:
- Literature review of desiccation tolerance in prokaryotes.
- Analysis of molecular and structural adaptations for water deficit survival.
- Examination of specific examples like cyanobacteria (Nostoc commune).
Main Results:
- Desiccation tolerance involves complex structural, physiological, and molecular interactions.
- Mechanisms differ significantly from those for salt, osmotic, or freeze-thaw stress.
- Cyanobacteria, like Nostoc commune, show adaptations like extracellular glycans and UV-absorbing pigments.
Conclusions:
- Water replacement by molecules like trehalose and sucrose aids membrane and protein preservation.
- The precise cytoplasmic state of desiccated cells remains largely unknown.
- Bacterial desiccation tolerance, despite its importance, has been understudied.