Editor: Michael Wagner
Light enhanced amino acid uptake by dominant bacterioplankton groups in surface waters of the Atlantic Ocean
Article first published online: 7 DEC 2007
FEMS Microbiology Ecology
Volume 63, Issue 1, pages 36–45, January 2008
How to Cite
Mary, I., Tarran, G. A., Warwick, P. E., Terry, M. J., Scanlan, D. J., Burkill, P. H. and Zubkov, M. V. (2008), Light enhanced amino acid uptake by dominant bacterioplankton groups in surface waters of the Atlantic Ocean. FEMS Microbiology Ecology, 63: 36–45. doi: 10.1111/j.1574-6941.2007.00414.x
- Issue published online: 7 DEC 2007
- Article first published online: 7 DEC 2007
- Received 18 August 2007; revised 10 October 2007; accepted 10 October 2007.First published online December 2007.
- marine phytoplankton;
- microbial photoheterotrophy;
- amino acid transport;
- flow cytometric sorting;
- dual tracer labelling
35S-Methionine and 3H-leucine bioassay tracer experiments were conducted on two meridional transatlantic cruises to assess whether dominant planktonic microorganisms use visible sunlight to enhance uptake of these organic molecules at ambient concentrations. The two numerically dominant groups of oceanic bacterioplankton were Prochlorococcus cyanobacteria and bacteria with low nucleic acid (LNA) content, comprising 60% SAR11-related cells. The results of flow cytometric sorting of labelled bacterioplankton cells showed that when incubated in the light, Prochlorococcus and LNA bacteria increased their uptake of amino acids on average by 50% and 23%, respectively, compared with those incubated in the dark. Amino acid uptake of Synechococcus cyanobacteria was also enhanced by visible light, but bacteria with high nucleic acid content showed no light stimulation. Additionally, differential uptake of the two amino acids by the Prochlorococcus and LNA cells was observed. The populations of these two types of cells on average completely accounted for the determined 22% light enhancement of amino acid uptake by the total bacterioplankton community, suggesting a plausible way of harnessing light energy for selectively transporting scarce nutrients that could explain the numerical dominance of these groups in situ.