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Living S. aureus bacteria rheology

2016-08Conference object Restricted access
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dc.contributor.authorPortela, R.
dc.contributor.authorFranco, J. M.
dc.contributor.authorPatricio, Pedro
dc.contributor.authorAlmeida, Pedro L.
dc.contributor.authorSobral, R. G.
dc.contributor.authorLeal, Catarina R.
dc.date.accessioned2020-11-13T12:02:34Z
dc.date.available2020-11-13T12:02:34Z
dc.date.issued2016-08
dc.description.abstractThe rheological characterization of Staphylococcus aureus cultures has shown a complex and rich viscoelastic behavior, during the bacteria population growth, when subject to a shear flow [1,2]. In particular, in stationary shear flow, the viscosity keeps increasing during the exponential phase reaching a maximum value (∼30x the initial value) after which it drops and returns close to its initial value in the stationary phase of growth, where the cell number of the bacterial population stabilizes. These behaviors can be associated with cell density and aggregation patterns that are developed during culture growth, showing a collective behavior. This behavior has no counterpart in the bacterial growth curve obtained by optical density monitorization (OD620nm and cfus/ml measurements). In oscillatory flow, the elastic and viscous moduli exhibit power-law behaviors whose exponents are dependent on the bacteria growth stage. These power-law dependencies of G’ and G’’ are in accordance with the Soft Glassy Material model [3], given by: G’~ ωx and G’’~ ωx To describe the observed behavior, a microscopic model considering the formation of a dynamic web-like structure was hypothesized [1], where percolation phenomena can occur, depending on the growth stage and on cell density. Recently, using real-time image rheology was possible to visualize the aggregation process associated with these dramatic changes in the viscoelastic behavior. In particular, the formation of web-like structures, at a specific time interval during the exponential phase of the bacteria growth and the cell sedimentation and subsequent enlargement of bacterial aggregates in the passage to the stationary phase of growth. These findings were essential to corroborate the microscopic model previously proposed and the main results of this study are compiled and presented in this work, see Fig.1.pt_PT
dc.description.versioninfo:eu-repo/semantics/publishedVersionpt_PT
dc.identifier.citationPORTELA, R.; [et al] – Living S. aureus bacteria rheology. In the XVIIth International Congress on Rheology (ICR2016). Kyoto, Japan. Pp. 1-2pt_PT
dc.identifier.urihttp://hdl.handle.net/10400.21/12376
dc.language.isoengpt_PT
dc.subjectRheological characterizationpt_PT
dc.subjectStaphylococcus aureus culturespt_PT
dc.subjectShear flowpt_PT
dc.subjectViscositypt_PT
dc.subjectOptical densitypt_PT
dc.subjectSoft Glassy Material modelpt_PT
dc.titleLiving S. aureus bacteria rheologypt_PT
dc.typeconference object
dspace.entity.typePublication
oaire.citation.conferencePlaceAug. 8 - 13, 2016 - Kyoto, Japanpt_PT
oaire.citation.endPage2pt_PT
oaire.citation.startPage1pt_PT
oaire.citation.titleThe XVIIth International Congress on Rheology (ICR2016)pt_PT
person.familyNamePatricio
person.familyNameMarques de Almeida
person.familyNameMarques Mendes Almeida da Rosa Leal
person.givenNamePedro
person.givenNamePedro
person.givenNameCatarina
person.identifierA-2814-2009
person.identifier.ciencia-idC616-BA77-E9C9
person.identifier.ciencia-id0218-71B2-2DE0
person.identifier.ciencia-idAF15-486E-BB15
person.identifier.orcid0000-0002-9050-9956
person.identifier.orcid0000-0001-7356-8455
person.identifier.orcid0000-0001-5871-4936
person.identifier.ridA-2750-2009
person.identifier.ridB-4356-2009
person.identifier.scopus-author-id57190384213
person.identifier.scopus-author-id7005379280
rcaap.rightsclosedAccesspt_PT
rcaap.typeconferenceObjectpt_PT
relation.isAuthorOfPublication11a2a1d5-8165-475a-8a54-e32bd8e8ce4e
relation.isAuthorOfPublication429b6d71-328e-42b3-8151-15493de249b8
relation.isAuthorOfPublication4db8990d-5eb1-4515-ae7a-68873cf776a5
relation.isAuthorOfPublication.latestForDiscovery11a2a1d5-8165-475a-8a54-e32bd8e8ce4e

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