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Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis

Multicellular fibres formed by Bacillus subtilis (B. subtilis) are attracting interest because of their potential application as degradable biomaterials. However, mechanical properties of individual fibres remain unknown because of their small dimensions. Herein, a new approach is developed to inves...

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Autores principales: Ye, Xuan, Zhao, Liang, Liang, Jiecun, Li, Xide, Chen, Guo-Qiang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380956/
https://www.ncbi.nlm.nih.gov/pubmed/28378797
http://dx.doi.org/10.1038/srep46052
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author Ye, Xuan
Zhao, Liang
Liang, Jiecun
Li, Xide
Chen, Guo-Qiang
author_facet Ye, Xuan
Zhao, Liang
Liang, Jiecun
Li, Xide
Chen, Guo-Qiang
author_sort Ye, Xuan
collection PubMed
description Multicellular fibres formed by Bacillus subtilis (B. subtilis) are attracting interest because of their potential application as degradable biomaterials. However, mechanical properties of individual fibres remain unknown because of their small dimensions. Herein, a new approach is developed to investigate the tensile properties of individual fibres with an average diameter of 0.7 μm and a length range of 25.7–254.3 μm. Variations in the tensile strengths of fibres are found to be the result of variable interactions among pairs of microbial cells known as septa. Using Weibull weakest-link model to study this mechanical variability, we predict the length effect of the sample. Moreover, the mechanical properties of fibres are found to depend highly on relative humidity (RH), with a brittle–ductile transition occurring around RH = 45%. The elastic modulus is 5.8 GPa in the brittle state, while decreases to 62.2 MPa in the ductile state. The properties of fibres are investigated by using a spring model (RH < 45%) for its elastic behaviour, and the Kelvin–Voigt model (RH > 45%) for the time-dependent response. Loading-unloading experiments and numerical calculations demonstrate that necking instability comes from structural changes (septa) and viscoelasticity dominates the deformation of fibres at high RH.
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spelling pubmed-53809562017-04-07 Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis Ye, Xuan Zhao, Liang Liang, Jiecun Li, Xide Chen, Guo-Qiang Sci Rep Article Multicellular fibres formed by Bacillus subtilis (B. subtilis) are attracting interest because of their potential application as degradable biomaterials. However, mechanical properties of individual fibres remain unknown because of their small dimensions. Herein, a new approach is developed to investigate the tensile properties of individual fibres with an average diameter of 0.7 μm and a length range of 25.7–254.3 μm. Variations in the tensile strengths of fibres are found to be the result of variable interactions among pairs of microbial cells known as septa. Using Weibull weakest-link model to study this mechanical variability, we predict the length effect of the sample. Moreover, the mechanical properties of fibres are found to depend highly on relative humidity (RH), with a brittle–ductile transition occurring around RH = 45%. The elastic modulus is 5.8 GPa in the brittle state, while decreases to 62.2 MPa in the ductile state. The properties of fibres are investigated by using a spring model (RH < 45%) for its elastic behaviour, and the Kelvin–Voigt model (RH > 45%) for the time-dependent response. Loading-unloading experiments and numerical calculations demonstrate that necking instability comes from structural changes (septa) and viscoelasticity dominates the deformation of fibres at high RH. Nature Publishing Group 2017-04-05 /pmc/articles/PMC5380956/ /pubmed/28378797 http://dx.doi.org/10.1038/srep46052 Text en Copyright © 2017, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Ye, Xuan
Zhao, Liang
Liang, Jiecun
Li, Xide
Chen, Guo-Qiang
Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis
title Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis
title_full Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis
title_fullStr Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis
title_full_unstemmed Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis
title_short Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis
title_sort study of the tensile properties of individual multicellular fibres generated by bacillus subtilis
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380956/
https://www.ncbi.nlm.nih.gov/pubmed/28378797
http://dx.doi.org/10.1038/srep46052
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