Growth of a Planktonic Green Alga at Various Carbonic Acid and Hydrogen-Ion Concentrations

Abstract

THE use of phosphate buffer mixtures when culturing Algæ has been shown to have several disadvantages. High phosphate concentrations are often injurious to Algæ, and in alkaline solutions precipitates of slightly soluble phosphates are formed, thus withdrawing from the Algæ elements necessary for growth. Nor has it been possible to make growth determinations at pH. higher than 8.2 on account of absorption of carbon dioxide from the air, which rapidly decreases the pH. In the experiments described here it has been possible partly to avoid these difficulties by using carbonate-bicarbonate buffer mixtures.