(CO2)-C-14 FIXATION PATTERN OF CYANOBACTERIA

The 14CO2 fixation patterns of three cyanobacteria [Microcystis firma, anabaena variabilis, synechocystis aquatilis] in the light and dark were studied. Two different chromatographic methods widely used for separating labelled photosynthetic intermediates were compared. After ethanolic extraction, a rather uniform fixation pattern reflecting mainly the .beta.-carboxylation pathway is obtained for all 3 species. Of the intermediates, glucosylglycerol is specific and high citrulline and low malate contents are fairly specific to cyanobacteria. The composition of the 14CO2 fixation pattern is hardly affected by changes in temperature or light intensity, but it is severely affected by changes in the water potential of the medium.