Mechanical properties of Bacillus subtilis cell walls: effects of ions and lysozyme
| Autor: | Alexander M. Jones, Uttam Surana, J J Thwaites |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Mineralogy
Young's modulus Biology Microbiology Cell wall chemistry.chemical_compound symbols.namesake Cell Wall Tensile Strength Ultimate tensile strength Stress relaxation Molecular Biology Elastic modulus Ions Osmolar Concentration Polyelectrolyte Chemical engineering chemistry Ammonium Sulfate Microscopy Electron Scanning symbols Muramidase Stress Mechanical Peptidoglycan Lysozyme Bacillus subtilis Research Article |
| Zdroj: | Europe PubMed Central |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.173.1.204-210.1991 |
| Popis: | Bacterial threads of Bacillus subtilis have been immersed in, and redrawn from, water of various pH values, in solutions of (NH4)2SO4 and NaCl of various concentrations, and in lysozyme solutions. The changes in the tensile strength, elastic modulus, and other mechanical properties of the bacterial cell wall due to these treatments were obtained. The data show that change in pH has little effect but that as the salt concentration is increased, the cell walls become more ductile. A high salt concentration (1 M NaCl) can reduce the modulus by a factor of 26 to 13.5 MPa at 81% relative humidity and the strength by a factor of only 2.5. Despite attacking the septal-wall region of the cellular filaments, lysozyme has no effect on the mechanical properties. There is no significant change in the stress relaxation behavior due to any of the treatments. The dependence of mechanical properties on the salt concentration is discussed in terms of the polyelectrolyte nature of cell walls. The evidence presented in this and the accompanying paper (J. J. Thwaites and U.C. Surana, J. Bacteriol., 173:197-203, 1991) supports the idea that the peptidoglycan in bacterial cell wall is an entanglement network with a large degree of molecular flexibility, with some order but no regular structure. |
| Databáze: | OpenAIRE |
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