Variation in cellular nutrient status within a population of Dinophysis norvegica (Dinophyceae) growing in situ: Single-cell elemental analysis by use of a nuclear microprobe
Lars-Åke Gisselson, Edna Granéli, Jan Pallon
Limnol. Oceanogr., 46(5), 2001, 1237–1242

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Elemental analysis (C, N, and P) of single cells of Dinophysis norvegica collected from the Baltic Sea was performed by use of a nuclear microprobe (NMP). For each cell, elemental maps were created and the cellular C, N, and P content was obtained. Concentrates of D. norvegica cells were collected simultaneously for measurement of particulate C, N, and P content by traditional methods for comparison. The traditional measurements of C, N, and P yielded 2.2–2.5 times higher values per cell than the ones obtained by the NMP method. Nevertheless, the averages for the elemental ratios were very similar for the traditional measurements and NMP. All the analyzed cells were deficient in both N and P, compared with the Redfield ratio. The data show that cellular nutrient status, especially cell quotas of N, can vary considerably within a population of one algal species growing under the same environmental conditions in situ.