Some Considerations of the Growth of Marine Algae in Artificial Media

Growth of 10 species of unicellular marine algae, representative of seven classes, in an enriched seawater medium was compared with growth in several artificial media. All media were buffered with glycylglycine, which was found to be less inhibitory than tris(hydroxymethyl)aminomethane. Growth of most species in natural seawater was superior to that in the artificial media examined, but the addition of 2 mM bicarbonate to these media resulted in improved growth comparable to that in the enriched seawater medium. All organisms were euryhaline and grew well in at least 50% seawater. Although considerable variation in the concentration of the major cations was tolerated, the concentration at which a particular cation limited growth was not the same for each species. Large changes in the magnesium-to-calcium ratio did not appear to affect growth, but a relation between sodium and magnesium and calcium was indicated for several organisms.