Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis

Autores
Inchaurrondo, V. A.; Flores, M. V.; Voget, Claudio Enrique
Año de publicación
1998
Idioma
español castellano
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Growth and β-galactosidase (β-gal) expression were characterized in the yeast Kluyveromyces lactis strain NRRL Y-1118 growing in aerobic chemostat cultures under carbon, nitrogen or phosphate limitation. In lactose or galactose-limited cultures, β-gal accumulated in amounts equivalent to 10-12% of the total cell protein. The induced β-gal expression was repressed when cells were grown under N- or P-limitation. In lactose medium, enzyme levels were 4-8 times lower than those expressed in C-limited cultures. A similar response was observed when galactose was the carbon source. These results suggest that a galactose-dependent signal (in addition to glucose) may have limited induction when cells were grown in carbon-sufficient cultures. Constitutive β-gal expression was highest in lactate-limited and lowest in glucose-limited media and was also repressed in glucose-sufficient cultures. Other K. lactis strains (NRRL Y-1140 and CBS 2360) also showed glucose repression (although with different sensitivity) under non-inducing conditions. We infer that these strains share a common mechanism of glucose repression independent of the induction pathway. The kinetics of β-gal induction observed in C-limited cultures confirms that β-gal induction is a short-term enzyme adaptation process. Applying a lactose pulse to a lactose-limited chemostat culture resulted in 'substrate-accelerated death'. Immediately after the pulse, growth was arrested and β-gal was progressively inactivated. Yeast metabolism in C-limited cultures was typically oxidative with the substrate being metabolized solely to biomass and CO 2 . Cells grown under P- or N-limitation, either with glucose or lactose, exhibited higher rates of sugar consumption than C-limited cells, accumulated intracellular reserve carbohydrates and secreted metabolic products derived from the glycolytic pathway, mainly glycerol and ethanol.
Centro de Investigación y Desarrollo en Fermentaciones Industriales
Materia
Ciencias Exactas
Biología
Kluyveromyces lactis
b-galactosidase
continuous culture
enzyme expression
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/140219

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network_name_str SEDICI (UNLP)
spelling Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactisInchaurrondo, V. A.Flores, M. V.Voget, Claudio EnriqueCiencias ExactasBiologíaKluyveromyces lactisb-galactosidasecontinuous cultureenzyme expressionGrowth and β-galactosidase (β-gal) expression were characterized in the yeast Kluyveromyces lactis strain NRRL Y-1118 growing in aerobic chemostat cultures under carbon, nitrogen or phosphate limitation. In lactose or galactose-limited cultures, β-gal accumulated in amounts equivalent to 10-12% of the total cell protein. The induced β-gal expression was repressed when cells were grown under N- or P-limitation. In lactose medium, enzyme levels were 4-8 times lower than those expressed in C-limited cultures. A similar response was observed when galactose was the carbon source. These results suggest that a galactose-dependent signal (in addition to glucose) may have limited induction when cells were grown in carbon-sufficient cultures. Constitutive β-gal expression was highest in lactate-limited and lowest in glucose-limited media and was also repressed in glucose-sufficient cultures. Other K. lactis strains (NRRL Y-1140 and CBS 2360) also showed glucose repression (although with different sensitivity) under non-inducing conditions. We infer that these strains share a common mechanism of glucose repression independent of the induction pathway. The kinetics of β-gal induction observed in C-limited cultures confirms that β-gal induction is a short-term enzyme adaptation process. Applying a lactose pulse to a lactose-limited chemostat culture resulted in 'substrate-accelerated death'. Immediately after the pulse, growth was arrested and β-gal was progressively inactivated. Yeast metabolism in C-limited cultures was typically oxidative with the substrate being metabolized solely to biomass and CO 2 . Cells grown under P- or N-limitation, either with glucose or lactose, exhibited higher rates of sugar consumption than C-limited cells, accumulated intracellular reserve carbohydrates and secreted metabolic products derived from the glycolytic pathway, mainly glycerol and ethanol.Centro de Investigación y Desarrollo en Fermentaciones Industriales1998-05-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf291-298http://sedici.unlp.edu.ar/handle/10915/140219spainfo:eu-repo/semantics/altIdentifier/issn/1367-5435info:eu-repo/semantics/altIdentifier/issn/1476-5535info:eu-repo/semantics/altIdentifier/doi/10.1038/sj.jim.2900526info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:32:03Zoai:sedici.unlp.edu.ar:10915/140219Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:32:03.456SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis
title Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis
spellingShingle Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis
Inchaurrondo, V. A.
Ciencias Exactas
Biología
Kluyveromyces lactis
b-galactosidase
continuous culture
enzyme expression
title_short Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis
title_full Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis
title_fullStr Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis
title_full_unstemmed Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis
title_sort Growth and β-galactosidase synthesis in aerobic chemostat cultures of Kluyveromyces lactis
dc.creator.none.fl_str_mv Inchaurrondo, V. A.
Flores, M. V.
Voget, Claudio Enrique
author Inchaurrondo, V. A.
author_facet Inchaurrondo, V. A.
Flores, M. V.
Voget, Claudio Enrique
author_role author
author2 Flores, M. V.
Voget, Claudio Enrique
author2_role author
author
dc.subject.none.fl_str_mv Ciencias Exactas
Biología
Kluyveromyces lactis
b-galactosidase
continuous culture
enzyme expression
topic Ciencias Exactas
Biología
Kluyveromyces lactis
b-galactosidase
continuous culture
enzyme expression
dc.description.none.fl_txt_mv Growth and β-galactosidase (β-gal) expression were characterized in the yeast Kluyveromyces lactis strain NRRL Y-1118 growing in aerobic chemostat cultures under carbon, nitrogen or phosphate limitation. In lactose or galactose-limited cultures, β-gal accumulated in amounts equivalent to 10-12% of the total cell protein. The induced β-gal expression was repressed when cells were grown under N- or P-limitation. In lactose medium, enzyme levels were 4-8 times lower than those expressed in C-limited cultures. A similar response was observed when galactose was the carbon source. These results suggest that a galactose-dependent signal (in addition to glucose) may have limited induction when cells were grown in carbon-sufficient cultures. Constitutive β-gal expression was highest in lactate-limited and lowest in glucose-limited media and was also repressed in glucose-sufficient cultures. Other K. lactis strains (NRRL Y-1140 and CBS 2360) also showed glucose repression (although with different sensitivity) under non-inducing conditions. We infer that these strains share a common mechanism of glucose repression independent of the induction pathway. The kinetics of β-gal induction observed in C-limited cultures confirms that β-gal induction is a short-term enzyme adaptation process. Applying a lactose pulse to a lactose-limited chemostat culture resulted in 'substrate-accelerated death'. Immediately after the pulse, growth was arrested and β-gal was progressively inactivated. Yeast metabolism in C-limited cultures was typically oxidative with the substrate being metabolized solely to biomass and CO 2 . Cells grown under P- or N-limitation, either with glucose or lactose, exhibited higher rates of sugar consumption than C-limited cells, accumulated intracellular reserve carbohydrates and secreted metabolic products derived from the glycolytic pathway, mainly glycerol and ethanol.
Centro de Investigación y Desarrollo en Fermentaciones Industriales
description Growth and β-galactosidase (β-gal) expression were characterized in the yeast Kluyveromyces lactis strain NRRL Y-1118 growing in aerobic chemostat cultures under carbon, nitrogen or phosphate limitation. In lactose or galactose-limited cultures, β-gal accumulated in amounts equivalent to 10-12% of the total cell protein. The induced β-gal expression was repressed when cells were grown under N- or P-limitation. In lactose medium, enzyme levels were 4-8 times lower than those expressed in C-limited cultures. A similar response was observed when galactose was the carbon source. These results suggest that a galactose-dependent signal (in addition to glucose) may have limited induction when cells were grown in carbon-sufficient cultures. Constitutive β-gal expression was highest in lactate-limited and lowest in glucose-limited media and was also repressed in glucose-sufficient cultures. Other K. lactis strains (NRRL Y-1140 and CBS 2360) also showed glucose repression (although with different sensitivity) under non-inducing conditions. We infer that these strains share a common mechanism of glucose repression independent of the induction pathway. The kinetics of β-gal induction observed in C-limited cultures confirms that β-gal induction is a short-term enzyme adaptation process. Applying a lactose pulse to a lactose-limited chemostat culture resulted in 'substrate-accelerated death'. Immediately after the pulse, growth was arrested and β-gal was progressively inactivated. Yeast metabolism in C-limited cultures was typically oxidative with the substrate being metabolized solely to biomass and CO 2 . Cells grown under P- or N-limitation, either with glucose or lactose, exhibited higher rates of sugar consumption than C-limited cells, accumulated intracellular reserve carbohydrates and secreted metabolic products derived from the glycolytic pathway, mainly glycerol and ethanol.
publishDate 1998
dc.date.none.fl_str_mv 1998-05-01
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/140219
url http://sedici.unlp.edu.ar/handle/10915/140219
dc.language.none.fl_str_mv spa
language spa
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1367-5435
info:eu-repo/semantics/altIdentifier/issn/1476-5535
info:eu-repo/semantics/altIdentifier/doi/10.1038/sj.jim.2900526
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
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Creative Commons Attribution 4.0 International (CC BY 4.0)
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