PARAGON 2 - KM2209 - Leucine Incorporation Timecourse Incubations

This dataset contains measurements of rates of leucine incorporation as a measure of bacterial production collected during the PARAGON 2 expedition (KM2209) in the North Pacific Subtropical Gyre. Measurements come from time-course incubation experiments initiated with whole seawater collected at 150 m using trace metal clean techniques and modified with various additions of organic carbon, iron, and/or nitrogen. Rates of leucine incorporation were measured at multiple time points for each experimental biological replicate by subsampling 1 mL aliquots from polycarbonate incubation bottles into 2 mL microcentrifuge tubes (Axygen) and spiking with a final concentration of 20 nmol L⁻¹ leucine with a ³H specific activity of 53.3 Ci mmol⁻¹ of leucine (Perkin Elmer). A killed blank measurement was made for each experimental biological replicate by spiking an additional 1 mL aliquot with 100 µL of 100% (w/v) ice-cold trichloroacetic acid (TCA) prior to spiking with ³H-leucine. All aliquots were then incubated in the dark at in situ temperature for 4-6 hours after which live incubations were terminated with the addition of 100 µL of 100% (w/v) ice-cold TCA. Samples were processed at sea using the centrifugation method of Smith and Azam (1992), and radioactivity incorporated into bacterial protein was measured on a TriCarb 4910TR scintillation counter using Ultima Gold LLT scintillation cocktail (Perkin Elmer). Values reported are the blank-corrected averages of technical triplicate measurements from each sample. Timestamp is in UTC.本数据集收录了北太平洋副热带环流（North Pacific Subtropical Gyre）PARAGON 2科考航次（KM2209）中采集的细菌生产力表征指标——亮氨酸掺入速率测量数据。该测量数据源自以痕量金属清洁采样技术，于150米水深采集的全海水样本启动的时间梯度培养实验，实验中添加了不同梯度的有机碳、铁及/或氮营养盐。针对每个实验生物学重复组，研究人员从聚碳酸酯培养瓶中移取1mL等分试样至2mL微量离心管（爱思进（Axygen）），加入终浓度为20 nmol·L⁻¹的亮氨酸（其³H标记物比活为53.3 Ci·mmol⁻¹，购自珀金埃尔默（Perkin Elmer）），并在多个时间点测定亮氨酸掺入速率。每个实验生物学重复组均设置灭活空白对照：在加入³H标记亮氨酸前，先向额外1mL等分试样中添加100μL 100%（w/v）冰三氯乙酸（TCA）。所有等分试样随后均在黑暗环境中以原位温度培养4至6小时，随后通过添加100μL 100%（w/v）冰三氯乙酸终止活样本培养。样本在科考船上采用Smith与Azam（1992）提出的离心法进行前处理，使用Ultima Gold LLT闪烁液（珀金埃尔默（Perkin Elmer））在TriCarb 4910TR液体闪烁计数器上测定掺入细菌蛋白的放射性活度。本数据集报告的数值为每个样本的三次技术重复测量结果经空白校正后的平均值。所有时间戳均采用协调世界时（UTC）。