Bacterial spores respond to humidity similarly to hydrogels

• 成果类型: Article
• 署名作者: Gor, Gennady Y.; Scherer, George W.; Stone, Howard A.
• 署名单位: New Jersey Institute of Technology; Princeton University; Princeton University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9353
• DOI: 10.1073/pnas.2320763121
• 发表日期: 2024-03-05
• 关键词: bacillus-subtilis spores; water-vapor; diffusion; sorption

摘要

Bacterial spores have outstanding properties from the materials science perspective, which allow them to survive extreme environmental conditions. Recent work by [S. G. Harrellson et al., Nature 619, 500-505 (2023)] studied the mechanical properties of Bacillus subtilis spores and the evolution of these properties with the change of humidity. The experimental measurements were interpreted assuming that the spores behave as water -filled porous solids, subjected to hydration forces. Here, we revisit their experimental data using literature data on vapor sorption on spores and ideas from polymer physics. We demonstrate that upon the change of humidity, the spores behave like rubber with respect to their swelling, elasticity, and relaxation times. This picture is consistent with the knowledge of the materials comprising the bacterial cell walls-cross-linked peptidoglycan. Our results provide an interpretation of the mechanics of bacterial spores and can help in developing synthetic materials mimicking the mechanical properties of the spores.