Dataset: Bacterial productivity of samples from three stations in the Western North Atlantic aboard R/V Atlantic Explorer cruise AE2413 during May 2024

Water for incubation  was collected via Niskin bottles mounted on a rosette, equipped with a CTD.  Bulk water was collected into an acid washed 50 mL Falcon tube directly from niskin bottles. 

Isotopically diluted L-[3,4,5-3H(N)]-Leucine (Revvity, NET460250UC, specific activity of 3.811 TBq/mmol) was added to 1.7ml triplicate subsamples and one TCA killed control (20 nM final concentration).  Samples and killed control were incubated between 5 and 48 hours at nearly in-situ temperature or 4°C.  Following incubation, live samples were killed with 100% (w/v) TCA and all samples were centrifuged (10,000 rpm at 4°C for 10 min) to pelletize cell material.  The supernatant liquid was removed and 1 mL of ice cold 5% (w/v) TCA solution was added, followed by vortex mixing and centrifugation.  Supernatant removal, mixing, and centrifugation were repeated using 1 mL of ice cold 80% ethanol solution.  Again, the supernatant liquid was removed and each sample was left to dry in a hood overnight.  After drying, 1 mL of scintillation cocktail (ScintiSafe 30% Cocktail, Fisher SX23-5) was added and left overnight so that precipitated proteins dissolve into scintillation fluid.  Incorporated radioactivity was measured using a PerkinElmer Tri-Carb 2910TR LSA scintillation counter.  Radioactivity was compared to 1 mL of scintillation cocktail spiked with an identical amount of isotopically diluted L-[3,4,5-3H(N)]-Leucine that was added to samples.  Incorporation rate was calculated by dividing sample radioactivity by incubation time.