Glucose Uptake inProchlorococcus:Diversity of Kinetics and Effects on the Metabolism.
We have previously shown thatProchlorococcussp. SS120 strain takes up glucose by using a multiphasic transporter encoded by the Pro1404 gene. Here, we studied the glucose uptake kinetics in multipleProchlorococcusstrains from different ecotypes, observing diverse values for the Ksconstants (15-126.60 nM) and the uptake rates (0.48-6.36 pmol min-1mg prot-1). Multiphasic kinetics was observed in all studied strains, except for TAK9803-2. Pro1404 gene expression studies during the 21st Atlantic Meridional Transect cruise showed positive correlation with glucose concentrations in the ocean. This suggests that the Pro1404 transporter has been subjected to diversification along theProchlorococcusevolution, in a process probably driven by the glucose availabilities at the different niches it inhabits. The glucose uptake mechanism seems to be a primary transporter. Glucose addition induced detectable transcriptomic and proteomic changes inProchlorococcusSS120, but photosynthetic efficiency was unaffected. Our studies indicate that glucose is actively taken up byProchlorococcus, but its uptake does not significantly alter the trophic ways of this cyanobacterium, which continues performing photosynthesis. ThereforeProchlorococcusseems to remain acting as a fundamentally phototrophic organism, capable of using glucose as an extra resource of carbon and energy when available in the environment.
Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba Córdoba, Spain.
María Del Carmen
MD
Muñoz-Marín
Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool Liverpool, UK.
Guadalupe
G
Gómez-Baena
Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba Córdoba, Spain.
Jesús
J
Díez
Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool Liverpool, UK.
Robert J
RJ
Beynon
Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba Córdoba, Spain.
David
D
González-Ballester
National Oceanography Centre Southampton, UK.
Mikhail V
MV
Zubkov
Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba Córdoba, Spain.
José M
JM
García-Fernández
gene expression; marine cyanobacteria; mixotrophy; proteomics; transporter kinetics