AME 73:235-243 (2014)  -  DOI: https://doi.org/10.3354/ame01720

Dissecting the role of viruses in marine nutrient cycling: bacterial uptake of d- and l-amino acids released by viral lysis

Emma J. Shelford1, Niels O. G. Jørgensen2, Susan Rasmussen3, Curtis A. Suttle1,4,5, Mathias Middelboe3,*

1Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
2Department of Plant and Environmental Sciences, Section of Genetics and Microbiology, University of Copenhagen, 1871 Frederiksberg, Denmark
3Marine Biological Section, University of Copenhagen, 3000 Helsingør, Denmark
4Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
5Department of Immunology and Microbiology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
*Corresponding author:

ABSTRACT: Lysis of marine bacteria by viruses releases a range of organic compounds into the environment, including d- and l-amino acids, but the uptake of these compounds by other bacteria is not well characterized. This study determined that Photobacterium sp. strain SKA34 (Gammaproteobacteria) increased in abundance following uptake of d- and l-amino acids from viral lysate of Cellulophaga sp. strain MM#3 (Flavobacteria). Ammonium and dissolved free amino acids were taken up almost to detection limits, suggesting that the C:N ratio of bioavailable organic matter in the lysate was high for Photobacterium sp. growth, thus causing a net uptake of ammonium. In contrast, only 1.51 µmol l-1 of the 4.77 µmol l-1 of the total dissolved combined amino acids (DCAAs) were taken up, indicating that a fraction of lysate-derived DCAAs were semi-labile or refractory to bacterial uptake. Both d- and l-amino acid uptake rates were approximately proportional to their concentrations, indicating similar availability for each enantiomer and unsaturated uptake rates. These results imply that under high C:N conditions, both d-amino acids (mainly found in bacterial cell walls) and l-amino acids (found in proteins of the rest of the cell) are equally available for bacterial growth, and support arguments that viruses are key players in marine nitrogen cycling.


KEY WORDS: Viral lysis · Marine bacteria · Amino acid · Nitrogen · Uptake · Nutrient cycling · Ammonium


Full text in pdf format 
Cite this article as: Shelford EJ, Jørgensen NOG, Rasmussen S, Suttle CA, Middelboe M (2014) Dissecting the role of viruses in marine nutrient cycling: bacterial uptake of d- and l-amino acids released by viral lysis. Aquat Microb Ecol 73:235-243. https://doi.org/10.3354/ame01720

Export citation
Mail this link - Contents Mailing Lists - RSS
- -