Effects of Temperature and Salinity on the Growth and the Optimum Nitrogen to Phosphorus Ratio for the Culture ofDiatoma tenueIsolated from a Temporary Arctic Pond in Svalbard, Norway

Abstract

We investigated the effects of temperature and salinity on the growth of Diatoma tenue isolated from a temporary arctic pond in a high-latitude region of Svalbard, Norway. We also examined the optimum nitrogen to phosphorus (N:P) ratio of the culture media. The highest growth rate (0.38 day") of D. tenue was achieved at 1 5'C, while growth was completely inhibited above 20°C. D. tenue could not grow when cultured at above 5%0 salinity. The final cell density of D. tenue was increased with an increasing phosphate concentration in the culture media from 0 to 5 pmol P L'. The final cell density became stable at above 5 pmol P I;' . The N:P molar ratio of the media containing 5 pmol P L-' was 34.8. These results show that D. tenue growth is limited by phosphorus at N:P ratios greater than 34.8, with a nitrogen limitation below 34.8. This finding indicates that this alga has a higher optimum N:P ratio than the Redfield ratio of 16.

Two New Benthic Diatoms of the Genus Achnanthidium (Bacillariophyceae) from the Hangang River, Korea

“…Cells were isolated and cultured in 96-well cell plates, and each well contained 160 μL of Diatom Medium (DM) [38]. After 10-14 days of isolation, diatoms reached the exponential growth stage [39]. The cells that grew and had a healthy aspect were transferred into 24-well cell plates with 1 mL of DM.…”

Phylogenetic position of eight Amphora sensu lato (Bacillariophyceae) species and comparative analysis of morphological characteristics

“…Single cells were isolated by the capillary method (Andersen 2005) under a Zeiss Axioplan 100 inverted microscope (Carl Zeiss, Jena, Germany) and cultured in 96-well plates containing 200 μL of f/2 medium (Guillard and Ryther 1962). The diatoms reached the exponential growth stage 7-10 days after inoculation (Katano et al 2007), and cells showing good growth were further subcultured into glass tubes with 15 mL of fresh f/2 medium at 10 days. All cultures were kept at 20°C in a 12 : 12-h light : dark cycle at 100-150 μmol m -2 s -1 provided by cool white fluorescent tubes.…”