Consequences of the formation of calcium phosphate solids on algal growth and polyphosphate storage

In this study, the authors investigated the ability of Chlorella pyrenoidosa and Anabaena flos-aquae to utilize solid phosphate for growth and accumulation of hot water extractable polyphosphate pools. Determination of the availability of solid phosphate formed in situ is complicated by: high pH and time required for solid formation; amount of phosphate removed from solution; and cellular nutrient status. Though abiotic experiments predicted persistence of the solid in the absence of algae, in batch cultures, solid phosphate was removed. In the presence of solid, growth rates and cellular phosphate were reduced, but solid phosphate was ultimately available to the algae.