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

Aquatic Microbial Ecology

Susan Rasmussen¹  Niels O. G. Jørgensen¹  Curtis A. Suttle¹  Emma J. Shelford¹  Mathias Middelboe¹ 

关键词: Viral lysis;    Marine bacteria;    Amino acid;    Nitrogen;    Uptake;    Nutrient cycling;    Ammonium;   

DOI  :  10.3354/ame01720

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

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.

【 授权许可】

Unknown