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Introducing Shear Stress in the Study of Bacterial Adhesion
Published on: September 2, 2011
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What keeps polyhydroxyalkanoates in bacterial cells amorphous? A derivation from stress exposure experiments
Petr Sedlacek1, Eva Slaninova1, Vojtech Enev1
1Faculty of Chemistry, Brno University of Technology, Purkynova 118, 612 00, Brno, Czech Republic.
Applied Microbiology and Biotechnology
|January 10, 2019
Summary
Bacterial polyhydroxyalkanoates (PHA) remain amorphous due to granule aggregation and cell drying, preventing crystallization. This study confirms water acts as a plasticizer, stabilizing amorphous PHA within granules.
Area of Science:
- Microbiology
- Polymer Science
- Biochemistry
Background:
- Polyhydroxyalkanoates (PHA) are bacterial storage polymers found as intracellular granules.
- Native PHA granules contain amorphous PHA, offering greater elasticity than crystalline PHA.
- Mechanisms stabilizing amorphous PHA in native granules remain unclear.
Purpose of the Study:
- To investigate the conditions and mechanisms responsible for maintaining the amorphous state of PHA in bacterial granules.
- To elucidate the role of granule aggregation and cell drying in PHA crystallization.
- To experimentally confirm the plasticizing effect of water on amorphous PHA.
Main Methods:
- Inducing PHA granule aggregation in bacterial cells via specific stressors.
- Subjecting stressed bacterial cells to drying conditions.
- Experimental confirmation of water's role as a plasticizer in PHA granules.
Main Results:
- Exposure to stressors induces PHA granule aggregation, a prerequisite for crystallization.
- PHA crystallization occurs only upon subsequent drying of stressed bacterial cells.
- Water present in PHA granules acts as a plasticizer, preventing polymer crystallization.
Conclusions:
- Both granule aggregation and cell drying are necessary and synergistic factors for PHA crystallization.
- The amorphous state of PHA is kinetically stabilized by limited crystallization rates within small granules.
- Water acts as a crucial plasticizer, experimentally confirmed to protect amorphous PHA from crystallization.
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