Effect of mechanical stress on biofilms challenged by different chemicals
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/1822/3751 |
Resumo: | In this study a methodology was applied in order to ascertain the mechanical stability of biofilms, by using a stainlesssteel (SS) rotating device immersed in a biological reactor where biofilms formed by Pseudomonas fluorescens were allowed to grow for 7 days at a Reynolds number of agitation of 2400. The biofilms developed with this system were characterised in terms of amount of total, extracellular and intracellular proteins and polysaccharides, amount of mass, metabolic activity and mechanical stability, showing that the biofilms were active, had a high content of extracellular constituents and an inherent mechanical stability. In order to assess the role of chemical agents on the mechanical stability, the biofilms were exposed to chemical agents followed by mechanical treatments by submission to increase Reynolds number of agitation. Seven different chemical agents were tested (two non-oxidising biocides, three surfactants and two oxidising biocides) and their effects on the biofilm mechanical stability were evaluated. The increase in the Reynolds number increased the biofilm removal, but total biofilm removal was not found for all the conditions tested. For the experiment without chemical addition (only mechanical treatment), the biofilm remaining on the surface was about 76%. The chemical treatment followed by the subsequent mechanical treatment did not remove all the biofilms from the surface. The biofilm remaining on the SS cylinder ranged from 3% to 62%, depending on the chemical treatment, showing that the chemical treatment is far from being a cause that induces massive biofilm detachment and even the synergistic chemical and mechanical treatments did not promote biofilm removal. Some chemical agents promoted an increase in the biofilm mechanical stability such as glutaraldehyde (GTA), benzalkonium chloride (BC), except for the lower concentration tested, and sodium dodecyl sulphate (SDS), except for the higher concentration tested. Treatments that promoted biofilm removal, to an extent similar to the control experiment (without chemical treatment), were BC, for the lower and the higher concentration of SDS. Cetyltrimethyl ammonium bromide (CTAB), ortho-phthalaldehyde (OPA), sodium hydroxide (NaOH) and sodium hypochlorite (SHC) promoted the weakening of the biofilm mechanical stability. |
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Effect of mechanical stress on biofilms challenged by different chemicalsBiofilm behaviourBiofilm controlChemical treatmentMechanical stabilityMechanical stressScience & TechnologyIn this study a methodology was applied in order to ascertain the mechanical stability of biofilms, by using a stainlesssteel (SS) rotating device immersed in a biological reactor where biofilms formed by Pseudomonas fluorescens were allowed to grow for 7 days at a Reynolds number of agitation of 2400. The biofilms developed with this system were characterised in terms of amount of total, extracellular and intracellular proteins and polysaccharides, amount of mass, metabolic activity and mechanical stability, showing that the biofilms were active, had a high content of extracellular constituents and an inherent mechanical stability. In order to assess the role of chemical agents on the mechanical stability, the biofilms were exposed to chemical agents followed by mechanical treatments by submission to increase Reynolds number of agitation. Seven different chemical agents were tested (two non-oxidising biocides, three surfactants and two oxidising biocides) and their effects on the biofilm mechanical stability were evaluated. The increase in the Reynolds number increased the biofilm removal, but total biofilm removal was not found for all the conditions tested. For the experiment without chemical addition (only mechanical treatment), the biofilm remaining on the surface was about 76%. The chemical treatment followed by the subsequent mechanical treatment did not remove all the biofilms from the surface. The biofilm remaining on the SS cylinder ranged from 3% to 62%, depending on the chemical treatment, showing that the chemical treatment is far from being a cause that induces massive biofilm detachment and even the synergistic chemical and mechanical treatments did not promote biofilm removal. Some chemical agents promoted an increase in the biofilm mechanical stability such as glutaraldehyde (GTA), benzalkonium chloride (BC), except for the lower concentration tested, and sodium dodecyl sulphate (SDS), except for the higher concentration tested. Treatments that promoted biofilm removal, to an extent similar to the control experiment (without chemical treatment), were BC, for the lower and the higher concentration of SDS. Cetyltrimethyl ammonium bromide (CTAB), ortho-phthalaldehyde (OPA), sodium hydroxide (NaOH) and sodium hypochlorite (SHC) promoted the weakening of the biofilm mechanical stability.Fundação para a Ciência e a Tecnologia (FCT).ElsevierUniversidade do MinhoSimões, M.Pereira, Maria OlíviaVieira, M. J.2005-122005-12-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/3751eng"Water Research". ISSN 0043-1354. 39:20 (2005) 5142-5152.0043-135410.1016/j.watres.2005.09.02816289205info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-21T12:50:17Zoai:repositorium.sdum.uminho.pt:1822/3751Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:48:57.475454Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Effect of mechanical stress on biofilms challenged by different chemicals |
title |
Effect of mechanical stress on biofilms challenged by different chemicals |
spellingShingle |
Effect of mechanical stress on biofilms challenged by different chemicals Simões, M. Biofilm behaviour Biofilm control Chemical treatment Mechanical stability Mechanical stress Science & Technology |
title_short |
Effect of mechanical stress on biofilms challenged by different chemicals |
title_full |
Effect of mechanical stress on biofilms challenged by different chemicals |
title_fullStr |
Effect of mechanical stress on biofilms challenged by different chemicals |
title_full_unstemmed |
Effect of mechanical stress on biofilms challenged by different chemicals |
title_sort |
Effect of mechanical stress on biofilms challenged by different chemicals |
author |
Simões, M. |
author_facet |
Simões, M. Pereira, Maria Olívia Vieira, M. J. |
author_role |
author |
author2 |
Pereira, Maria Olívia Vieira, M. J. |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Simões, M. Pereira, Maria Olívia Vieira, M. J. |
dc.subject.por.fl_str_mv |
Biofilm behaviour Biofilm control Chemical treatment Mechanical stability Mechanical stress Science & Technology |
topic |
Biofilm behaviour Biofilm control Chemical treatment Mechanical stability Mechanical stress Science & Technology |
description |
In this study a methodology was applied in order to ascertain the mechanical stability of biofilms, by using a stainlesssteel (SS) rotating device immersed in a biological reactor where biofilms formed by Pseudomonas fluorescens were allowed to grow for 7 days at a Reynolds number of agitation of 2400. The biofilms developed with this system were characterised in terms of amount of total, extracellular and intracellular proteins and polysaccharides, amount of mass, metabolic activity and mechanical stability, showing that the biofilms were active, had a high content of extracellular constituents and an inherent mechanical stability. In order to assess the role of chemical agents on the mechanical stability, the biofilms were exposed to chemical agents followed by mechanical treatments by submission to increase Reynolds number of agitation. Seven different chemical agents were tested (two non-oxidising biocides, three surfactants and two oxidising biocides) and their effects on the biofilm mechanical stability were evaluated. The increase in the Reynolds number increased the biofilm removal, but total biofilm removal was not found for all the conditions tested. For the experiment without chemical addition (only mechanical treatment), the biofilm remaining on the surface was about 76%. The chemical treatment followed by the subsequent mechanical treatment did not remove all the biofilms from the surface. The biofilm remaining on the SS cylinder ranged from 3% to 62%, depending on the chemical treatment, showing that the chemical treatment is far from being a cause that induces massive biofilm detachment and even the synergistic chemical and mechanical treatments did not promote biofilm removal. Some chemical agents promoted an increase in the biofilm mechanical stability such as glutaraldehyde (GTA), benzalkonium chloride (BC), except for the lower concentration tested, and sodium dodecyl sulphate (SDS), except for the higher concentration tested. Treatments that promoted biofilm removal, to an extent similar to the control experiment (without chemical treatment), were BC, for the lower and the higher concentration of SDS. Cetyltrimethyl ammonium bromide (CTAB), ortho-phthalaldehyde (OPA), sodium hydroxide (NaOH) and sodium hypochlorite (SHC) promoted the weakening of the biofilm mechanical stability. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005-12 2005-12-01T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/1822/3751 |
url |
http://hdl.handle.net/1822/3751 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
"Water Research". ISSN 0043-1354. 39:20 (2005) 5142-5152. 0043-1354 10.1016/j.watres.2005.09.028 16289205 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799133069474529280 |