Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms

161 p.

Saved in:

Bibliographic Details
Main Author:	Chew, Su Chuen
Other Authors:	Staffan Kjelleberg
Format:	Theses and Dissertations
Language:	English
Published:	2016
Subjects:	DRNTU::Science::Biological sciences::Microbiology::Bacteria
Online Access:	http://hdl.handle.net/10356/69126
Tags:	Add Tag No Tags, Be the first to tag this record!
Institution:	Nanyang Technological University
Language:	English

id	sg-ntu-dr.10356-69126
record_format	dspace
spelling	sg-ntu-dr.10356-691262020-11-13T04:36:41Z Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms Chew, Su Chuen Staffan Kjelleberg Scott Rice Interdisciplinary Graduate School (IGS) Singapore Centre for Environmental Life Sciences Engineering (SCELSE) DRNTU::Science::Biological sciences::Microbiology::Bacteria 161 p. Microbial cells secrete extracellular polymeric substances (EPS) to encase themselves in a matrix and form assemblages known as biofilms. Microbial biofilms are notoriously difficult to eradicate, and can cause fouling of technical systems and be detrimental to health when they are formed by pathogenic bacteria in our bodies to cause infection. Despite the EPS forming the major constituent of most biofilms (approximately 50-90% total organic matter), relatively less is known about the EPS as compared to cell signaling and molecular pathways involved in biofilm formation. As EPS components define the mechanical properties of biofilms, they impact on multicellular structural organization and have consequences for biofilm stability, dissemination and downstream colonization in flow environments. Furthermore, EPS components can be heterogeneously distributed in the biofilm, highlighting the need to carry out biofilm investigations at the micro-scale. In this thesis, particle tracking microrheology and micropillars were used to quantify the mechanical properties of specific EPS components at microscale resolution, and how these properties related to biofilm functions were investigated. In opportunistic pathogen P. aeruginosa, which uses Psl and Pel exopolysaccharides as major EPS components, it was found that Psl contributed to a more elastic and effectively crosslinked matrix that resisted spreading at the surface but facilitated microcolony formation. In contrast, Pel contributed to a more viscoelastic and loose matrix that facilitated surface spreading, lateral growth and streamer formation. Psl and Pel also contributed differentially but synergistically to heterogeneous lateral growth. The rheological roles of Psl and Pel were largely maintained in P. aeruginosa-S.aureus community biofilms, where Psl increased the crosslinking of the matrix and was required for the community microcolony formation, and Pel loosened and increased particle diffusivity in the matrix, which likely facilitated microcolony expansion. Singapore Centre for Environmental Life Sciences Engineering (SCELSE), whose research is funded by the National Research Foundation Singapore (NRF), Ministry of Education Singapore (MOE), Nanyang Technological University (NTU) and National University of Singapore (NUS) , under its Research Centre of Excellence (RCE) program; Singapore MIT Alliance for Research and Technology’s (SMART) research program in BioSystems and Micromechanics supported by the National Research Foundation Singapore. Doctor of Philosophy (IGS) 2016-11-09T01:35:31Z 2016-11-09T01:35:31Z 2016 Thesis Chew, S. C. (2016). Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms. Doctoral thesis, Nanyang Technological University, Singapore. http://hdl.handle.net/10356/69126 10.32657/10356/69126 en application/pdf
institution	Nanyang Technological University
building	NTU Library
continent	Asia
country	Singapore Singapore
content_provider	NTU Library
collection	DR-NTU
language	English
topic	DRNTU::Science::Biological sciences::Microbiology::Bacteria
spellingShingle	DRNTU::Science::Biological sciences::Microbiology::Bacteria Chew, Su Chuen Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms
description	161 p.
author2	Staffan Kjelleberg
author_facet	Staffan Kjelleberg Chew, Su Chuen
format	Theses and Dissertations
author	Chew, Su Chuen
author_sort	Chew, Su Chuen
title	Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms
title_short	Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms
title_full	Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms
title_fullStr	Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms
title_full_unstemmed	Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms
title_sort	mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms
publishDate	2016
url	http://hdl.handle.net/10356/69126
_version_	1688665313682391040

Mechanical and functional characterization of extracellular polymeric substances of bacterial biofilms

Similar Items