Ambient concentrations, microbial turnover rates and turnover times of methionine, leucine and organic phosphate measured on cruise AMT20 (JC053)

This dataset consists of microbial uptake, turnover rates and ambient concentration measurements of organic substrates collected during the Atlantic Meridional Transect programme cruise 20 (AMT20, JC053) between 14th October and 21st November 2010. The cruise track between UK and Chile passed through both North and South Atlantic gyres. This dataset is a contribution to the AMT time-series of core oceanographic measurements. For the amino acids methionine and leucine a total of 54 experiments to determine microbial uptake, turnover rates and ambient concentration were carried out. For adenosine-tri-phosphate, as a marker for organic phosphate uptake, 23 measurements were conducted. Samples were incubated with different concentrations of 3H-labelled leucine, ³⁵S-labelled methionine or ³³P-labelled adenosine-tri-phosphate (organic phosphate) and subsamples fixed with 1% w/v paraformaldehyde at specific time points. Samples were then filtered on 0.2 &micron;m polycarbonate filters to collect and measure the radiolabelled substrate within the cells using a liquid scintillation counter (TriCarb3100, PerkinElmer).