AN INVIVO METHOD FOR THE ESTIMATION OF PHYCOERYTHRIN CONCENTRATIONS IN MARINE CYANOBACTERIA (SYNECHOCOCCUS SPP)

A new, rapid and simple method estimates phycoerythrin (PE) concentrations in natural populations of marine Synechococcus spp. The method is based on the observation that glycerol uncouples energy transfer between PE and other biliproteins of the Synechococcus phycobilisome. Under these conditions there is a precise linear relation between the intensity of PE fluorescence emission and cell PE content. The method was used to determine profiles of Synechococcus PE for neritic (Celtic Sea) and open-ocean (Sargasso Sea) waters. Both profiles show that cell PE increased with depth and reflect the influence that the availability of light and nutrients (nitrogen) has on the synthesis of this biliprotein.