Preliminary observations of the physiology ofMelosira italicasubspeciessubarctica: Culture medium and cell composition

Abstract

A new medium is described for the growth of the freshwater diatom Melosira italica subsp. subarctica which allows prolonged exponential growth in batch culture. The medium was optimized for cell yield and observations are reported on varying the pH, shaking rate and trace-metal concentrations in the medium. The medium contained no vitamins. Preliminary results suggest that the silica usage was 0·163 mg Si mm^-3 filament volume, the molar ratio of Si:P uptake varied between 46:1 during exponential growth and 30:1 during silica limitation; the molar N:P ratio of the cells averaged 5·6:1.