Concentrations, turnover rates and fluxes of polyamines in coastal waters of the South Atlantic Bight during April and October 2011

Polyamines are short-chain aliphatic compounds containing multiple amine groups. They are important components of the cytosol of eukaryotes and are present at mmol/L concentrations inside phytoplankton cells, while complex polyamines play a role in biosilica deposition. Concentrations of polyamines measured in seawater are typically in the sub nmol/L range, implying rapid and efficient uptake by osmotrophs, likely bacterioplankton. We measured turnover rates of three polyamines (putrescine, spermidine and spermine) using 3H-labeled compounds and determined their concentrations by HPLC to estimate polyamine contributions to dissolved organic matter and bacterioplankton carbon and nitrogen demand. These measurements were made on transects from the inner shelf to the Gulf Stream across the South Atlantic Bight (SAB) during April and October of 2011 and in salt marsh estuaries on the Georgia coast during August of 2011 and April of 2012. This data set includes measurements of water column variables (temperature, salinity, biogenic Silica), nutrients (nitrite, nitrate+nitrite, ammonium and dissolved inorganic nitrogen), and concentrations and turnover rates of polyamine compounds.

多胺（Polyamines）是含有多个氨基的短链脂肪族化合物。它们是真核生物胞质溶胶（cytosol）的重要组分，在浮游植物细胞内的浓度可达mmol/L级别；而复杂多胺则参与生物硅（biosilica）沉积过程。海水中测得的多胺浓度通常处于亚纳摩尔每升（sub nmol/L）范围，这表明渗透营养生物（osmotrophs）——很可能是浮游细菌（bacterioplankton）——对其具有快速且高效的吸收能力。我们采用³H标记化合物测定了三种多胺（腐胺putrescine、亚精胺spermidine、精胺spermine）的周转速率，并通过高效液相色谱（HPLC）分析其浓度，以评估多胺对溶解有机物（dissolved organic matter, DOM）及浮游细菌碳氮需求的贡献。这些测定分别于2011年4月和10月在横跨南大西洋湾（South Atlantic Bight, SAB）的陆架内侧至墨西哥湾流（Gulf Stream）断面，以及2011年8月和2012年4月在佐治亚州（Georgia）海岸的盐沼河口区域开展。本数据集包含水柱变量（温度、盐度、生物硅）、营养盐（亚硝酸盐、硝酸盐+亚硝酸盐、铵盐及溶解无机氮），以及多胺化合物的浓度和周转速率等测定数据。