The effect of calcium on the growth ofChlorella andScenedesmus

The paper deals with the problem of the significance of Ca²⁺ for the growth of algae, its participation in the process of nitrate and ammonium nitrogen utilization, and with the possibility of substituting Sr²⁺ for it. It was revealed that calcium represents a microbiogenous element for the algae tested, which takes part in the utilization of nitrate nitrogen. It cannot be replaced by strontium especially at a high growth rate of mixotrophically cultivated algae (ina glucose medium).