Chemical composition of Skeletonema costatum (Grev.) Cleve and Paplova (Monochrysis) lutheri (Droop) Green as a function of nitrate-, phosphate-, and iron-limited growth
Sakshaug, E.; Holm-Hansen, O. (1977). Chemical composition of Skeletonema costatum (Grev.) Cleve and Paplova (Monochrysis) lutheri (Droop) Green as a function of nitrate-, phosphate-, and iron-limited growth. J. Exp. Mar. Biol. Ecol. 29(1): 1-34. https://dx.doi.org/10.1016/0022-0981(77)90118-6
In: Journal of Experimental Marine Biology and Ecology. Elsevier: New York. ISSN 0022-0981; e-ISSN 1879-1697, more
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| Keywords |
Composition > Chemical composition
Limiting factors
Pavlova lutheri (Droop) J.C.Green, 1975 [WoRMS]; Skeletonema costatum (Greville) Cleve, 1873 [WoRMS]
Marine/Coastal |
| Authors | | Top |
- Sakshaug, E.
- Holm-Hansen, O.
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| Abstract |
The variation in chemical composition of S. costatum and P. lutheri was studied in batch cultures with N-, P-, and Fe-deficient media under continuous light. In vivo fluorescence, chlorophyll a, ATP, cellular nitrogen, carbon, and phosphorus, and cell density were measured. The exponential growth rate was 2 . 9-3 . 5 doubl. Day-1 for Skeletonema and 1 . 2-1 . 9 doubl. Day-1 for Pavlova, with the lower rates pertaining to cultures in Fe-deficient media. In exponentially growing cultures nitrogen and carbon per cell increased with an increasing N/P ratio of the media, whereas chlorophyll a, ATP, and organic phosphorus per cell remained relatively constant. In Fe-deficient cells nitrogen and carbon per cell was high, as for cells in media with a high N/P ratio. The total variation in exponential cells was contained within a factor of three. Larger differences in chemical composition were found between exponentially growing cells and nutrient deficient cells. For all types of nutrient deficiency the chl/N and chl/C ratios decreased when cells went from the exponential phase to the starvation phase. The ratio between in vivo fluorescence and chlorophyll a increased 4-5 fold. The C/N ratio (atomic) of both species increased from 5-7 . 5 for exponentially growing cells up to 35 during N-deficiency and up to 13 during P-deficiency. For cells in Fe-deficient medium values were scattered in the 7-11 range. ATP and organic phosphorus followed each other closely and had values which were about 3 times higher in Skeletonema than in Pavlova when using any other parameter as a frame of reference for identical media and growth stages. In N-deficient media the N/ATP ratio was virtually the same for exponentially growing cells and starved cells. The C/ATP ratio reached high levels in nutrient deficient cells, with a maximum of 9000 for P-deficient cells of Pavlova. Both species had a minimum value of polyphosphates corresponding to about 10% of the total phosphorus. In P-rich media Pavlova had storage polyphosphates up to 70% of the total P. Storage polyphosphates were not observed in Skeletonema. With the set of factors used it is possible to identify growth stages and type of nutrient deficiency for a given culture. It is indicated that, with certain limitations, this approach may be applicable in field studies. |
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