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Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus

The marine cyanobacteria Prochlorococcus have been considered photoautotrophic microorganisms, although the utilization of exogenous sugars has never been specifically addressed in them. We studied glucose uptake in different high irradiance- and low irradiance-adapted Prochlorococcus strains, as we...

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Autores principales: Gómez-Baena, Guadalupe, López-Lozano, Antonio, Gil-Martínez, Jorge, Lucena, José Manuel, Diez, Jesús, Candau, Pedro, García-Fernández, Jose Manuel
Formato: Texto
Lenguaje:English
Publicado: Public Library of Science 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2565063/
https://www.ncbi.nlm.nih.gov/pubmed/18941506
http://dx.doi.org/10.1371/journal.pone.0003416
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author Gómez-Baena, Guadalupe
López-Lozano, Antonio
Gil-Martínez, Jorge
Lucena, José Manuel
Diez, Jesús
Candau, Pedro
García-Fernández, Jose Manuel
author_facet Gómez-Baena, Guadalupe
López-Lozano, Antonio
Gil-Martínez, Jorge
Lucena, José Manuel
Diez, Jesús
Candau, Pedro
García-Fernández, Jose Manuel
author_sort Gómez-Baena, Guadalupe
collection PubMed
description The marine cyanobacteria Prochlorococcus have been considered photoautotrophic microorganisms, although the utilization of exogenous sugars has never been specifically addressed in them. We studied glucose uptake in different high irradiance- and low irradiance-adapted Prochlorococcus strains, as well as the effect of glucose addition on the expression of several glucose-related genes. Glucose uptake was measured by adding radiolabelled glucose to Prochlorococcus cultures, followed by flow cytometry coupled with cell sorting in order to separate Prochlorococcus cells from bacterial contaminants. Sorted cells were recovered by filtration and their radioactivity measured. The expression, after glucose addition, of several genes (involved in glucose metabolism, and in nitrogen assimilation and its regulation) was determined in the low irradiance-adapted Prochlorococcus SS120 strain by semi-quantitative real time RT-PCR, using the rnpB gene as internal control. Our results demonstrate for the first time that the Prochlorococcus strains studied in this work take up glucose at significant rates even at concentrations close to those found in the oceans, and also exclude the possibility of this uptake being carried out by eventual bacterial contaminants, since only Prochlorococcus cells were used for radioactivity measurements. Besides, we show that the expression of a number of genes involved in glucose utilization (namely zwf, gnd and dld, encoding glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and lactate dehydrogenase, respectively) is strongly increased upon glucose addition to cultures of the SS120 strain. This fact, taken together with the magnitude of the glucose uptake, clearly indicates the physiological importance of the phenomenon. Given the significant contribution of Prochlorococcus to the global primary production, these findings have strong implications for the understanding of the phytoplankton role in the carbon cycle in nature. Besides, the ability of assimilating carbon molecules could provide additional hints to comprehend the ecological success of Prochlorococcus.
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spelling pubmed-25650632008-10-20 Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus Gómez-Baena, Guadalupe López-Lozano, Antonio Gil-Martínez, Jorge Lucena, José Manuel Diez, Jesús Candau, Pedro García-Fernández, Jose Manuel PLoS One Research Article The marine cyanobacteria Prochlorococcus have been considered photoautotrophic microorganisms, although the utilization of exogenous sugars has never been specifically addressed in them. We studied glucose uptake in different high irradiance- and low irradiance-adapted Prochlorococcus strains, as well as the effect of glucose addition on the expression of several glucose-related genes. Glucose uptake was measured by adding radiolabelled glucose to Prochlorococcus cultures, followed by flow cytometry coupled with cell sorting in order to separate Prochlorococcus cells from bacterial contaminants. Sorted cells were recovered by filtration and their radioactivity measured. The expression, after glucose addition, of several genes (involved in glucose metabolism, and in nitrogen assimilation and its regulation) was determined in the low irradiance-adapted Prochlorococcus SS120 strain by semi-quantitative real time RT-PCR, using the rnpB gene as internal control. Our results demonstrate for the first time that the Prochlorococcus strains studied in this work take up glucose at significant rates even at concentrations close to those found in the oceans, and also exclude the possibility of this uptake being carried out by eventual bacterial contaminants, since only Prochlorococcus cells were used for radioactivity measurements. Besides, we show that the expression of a number of genes involved in glucose utilization (namely zwf, gnd and dld, encoding glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and lactate dehydrogenase, respectively) is strongly increased upon glucose addition to cultures of the SS120 strain. This fact, taken together with the magnitude of the glucose uptake, clearly indicates the physiological importance of the phenomenon. Given the significant contribution of Prochlorococcus to the global primary production, these findings have strong implications for the understanding of the phytoplankton role in the carbon cycle in nature. Besides, the ability of assimilating carbon molecules could provide additional hints to comprehend the ecological success of Prochlorococcus. Public Library of Science 2008-10-20 /pmc/articles/PMC2565063/ /pubmed/18941506 http://dx.doi.org/10.1371/journal.pone.0003416 Text en Gómez-Baena et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Gómez-Baena, Guadalupe
López-Lozano, Antonio
Gil-Martínez, Jorge
Lucena, José Manuel
Diez, Jesús
Candau, Pedro
García-Fernández, Jose Manuel
Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus
title Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus
title_full Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus
title_fullStr Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus
title_full_unstemmed Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus
title_short Glucose Uptake and Its Effect on Gene Expression in Prochlorococcus
title_sort glucose uptake and its effect on gene expression in prochlorococcus
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2565063/
https://www.ncbi.nlm.nih.gov/pubmed/18941506
http://dx.doi.org/10.1371/journal.pone.0003416
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