Organic N uptake

In addition to complicating our view of the marine N cycle, high rates of inorganic N uptake by bacteria and organic N uptake by phytoplankton may compromise stoichiometric calculation of C assimilation from N uptake (or vice versa) using the Redfield C N ratio in the euphotic zone (Wheeler and Kirchman, 1986). Further, bacterial uptake of NH4+ and NOs can confound computation of the f-ratio leading to over- or underestimates of new production. Consequently, estimating C export from N-based estimates of new production needs to be reevaluated for a variety of reasons. 

Lightfoot, D.A., Green, N.K. Cullimore, J.V. (1988). The chloroplast-located glutamine synthetase of Phaseolus vulgaris L. Nucleotide sequence, expression in different organs and uptake into isolated chloroplasts. Plant Molecular Biology 11, 191-202. 

Bronk, D. A., and Glibert, P. M. (1993). Application of a N tracer method to the study of dissolved organic nitrogen uptake during spring and summer in Chesapeake Bay. Mar. Biol. 115, 501—508. 

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