The azoreductase of yeast cells: a new feature of an old enzyme

Bibliographic Details
Main Author: Ramalho, Patrícia Alexandra Costa Ferreira
Publication Date: 2004
Other Authors: Paiva, Sandra, Paulo, Artur Cavaco, Casal, Margarida, Ramalho, Maria Teresa, Cardoso, M. Helena
Language: eng
Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
Download full: https://hdl.handle.net/1822/2227
Summary: Apresentação efectuada nas Jornadas de Biologia de Leveduras “Professor Nicolau van Uden”, 12, Universidade de Aveiro, Portugal, 13-15 Maio 2004.
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spelling The azoreductase of yeast cells: a new feature of an old enzymeAzoreductaseFerric reductaseApresentação efectuada nas Jornadas de Biologia de Leveduras “Professor Nicolau van Uden”, 12, Universidade de Aveiro, Portugal, 13-15 Maio 2004.In an attempt to develop a biological treatment for colour removal we isolated several ascomycete yeast strains from contaminated soil based on its capacity to decolourize soluble azo dyes. We studied the process in batch cultures and have demonstrated that the colour loss was due to a reductase activity, expressed constitutively, which could transform azo dyes into colourless amines [1]. To understand the process behind the azo decolourising capacity of some yeast strains isolated by our group [1,2] we selected a Saccharomyces cerevisiae strain (BLC0276) with this capacity. This strain was able to decolourize the media in 8 to 16 h. With evidences from a previous work and with the knowledge that the plasma membrane redox systems are known to be ubiquitous and multifunctional, we decided to explore the involvement of one of these systems on this feature of S.cerevisiae – the ferric reductase system. This system is responsible for the reduction of ferric to ferrous iron previous to its uptake by the yeast cell. First we compared both ferric and azo reducing activities along the growth phases. Both have an activity peak in the late exponential growth phase. These peaks correspond in growing cultures to the phase where the dye is more actively removed. Then several known inhibitors were added to the media, like carbonylcyanide m-chlorophenylhydrazone (CCCP), diphenylene iodonium (DPI), p-chloromercuribenzoate (pCMB) and chloroquine (CQ), and different levels of inhibition on both ferric and azo reductase activities were observed. The genes Fre1 and Fre2 were deleted and the effect on the decolourising activity was analysed in the mutant strains. Once again the process was retarded in fre1 and fre1fre2 strains. The effect of Fre2 deletion was negligible. The deletion of Fre1 retarded the decolourising capability showing the involvement of this system in the azo decolorizing capacity of S.cerevisiae. However the capacity was not completely removed indicating that cells have an alternative reducing system. [1] Ramalho, P.A., Scholze, H., Cardoso, M.H., Ramalho, M.T., Oliveira-Campos, A.M. 2002 Improved conditions for the aerobic reductive decolourization of azo dyes by Candida zeylanoides. Enz Microbiol Technol 31: 848-854. [2] Ramalho, P.A., Cardoso, M.H., Cavaco-Paulo, A., Ramalho, M.T. 2004 Characterisation of the azo reductase activity in a novel ascomycete yeast strain. Accepted for publication in Appl Environ Microbiol 70BIOEFTEX Project.Universidade do MinhoRamalho, Patrícia Alexandra Costa FerreiraPaiva, SandraPaulo, Artur CavacoCasal, MargaridaRamalho, Maria TeresaCardoso, M. Helena2004-052004-05-01T00:00:00Zconference objectinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/1822/2227enginfo:eu-repo/semantics/openAccessreponame:Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)instname:FCCN, serviços digitais da FCT – Fundação para a Ciência e a Tecnologiainstacron:RCAAP2025-03-15T01:16:46Zoai:repositorium.sdum.uminho.pt:1822/2227Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireinfo@rcaap.ptopendoar:https://opendoar.ac.uk/repository/71602025-05-28T14:58:45.516081Repositórios Científicos de Acesso Aberto de Portugal (RCAAP) - FCCN, serviços digitais da FCT – Fundação para a Ciência e a Tecnologiafalse
dc.title.none.fl_str_mv The azoreductase of yeast cells: a new feature of an old enzyme
title The azoreductase of yeast cells: a new feature of an old enzyme
spellingShingle The azoreductase of yeast cells: a new feature of an old enzyme
Ramalho, Patrícia Alexandra Costa Ferreira
Azoreductase
Ferric reductase
title_short The azoreductase of yeast cells: a new feature of an old enzyme
title_full The azoreductase of yeast cells: a new feature of an old enzyme
title_fullStr The azoreductase of yeast cells: a new feature of an old enzyme
title_full_unstemmed The azoreductase of yeast cells: a new feature of an old enzyme
title_sort The azoreductase of yeast cells: a new feature of an old enzyme
author Ramalho, Patrícia Alexandra Costa Ferreira
author_facet Ramalho, Patrícia Alexandra Costa Ferreira
Paiva, Sandra
Paulo, Artur Cavaco
Casal, Margarida
Ramalho, Maria Teresa
Cardoso, M. Helena
author_role author
author2 Paiva, Sandra
Paulo, Artur Cavaco
Casal, Margarida
Ramalho, Maria Teresa
Cardoso, M. Helena
author2_role author
author
author
author
author
dc.contributor.none.fl_str_mv Universidade do Minho
dc.contributor.author.fl_str_mv Ramalho, Patrícia Alexandra Costa Ferreira
Paiva, Sandra
Paulo, Artur Cavaco
Casal, Margarida
Ramalho, Maria Teresa
Cardoso, M. Helena
dc.subject.por.fl_str_mv Azoreductase
Ferric reductase
topic Azoreductase
Ferric reductase
description Apresentação efectuada nas Jornadas de Biologia de Leveduras “Professor Nicolau van Uden”, 12, Universidade de Aveiro, Portugal, 13-15 Maio 2004.
publishDate 2004
dc.date.none.fl_str_mv 2004-05
2004-05-01T00:00:00Z
dc.type.driver.fl_str_mv conference object
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
status_str publishedVersion
dc.identifier.uri.fl_str_mv https://hdl.handle.net/1822/2227
url https://hdl.handle.net/1822/2227
dc.language.iso.fl_str_mv eng
language eng
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.source.none.fl_str_mv reponame:Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
instname:FCCN, serviços digitais da FCT – Fundação para a Ciência e a Tecnologia
instacron:RCAAP
instname_str FCCN, serviços digitais da FCT – Fundação para a Ciência e a Tecnologia
instacron_str RCAAP
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reponame_str Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
collection Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
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repository.mail.fl_str_mv info@rcaap.pt
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