Photosynthesis and Respiration of Three Blue-Green Algae.

Abstract

Photo-synthesis and respiration of three blue-green algae, Anabaena variabilis, Anacystis nidulans, and Nostoc muscorum G, have been studied by conventional Warburg manometry. Rates of photosynthesis at light saturation were measured in the Warburg series of carbonate-bicarbonate buffers and in bicarbonate-carbon dioxide buffers in the pH range 6 to 10.5. Evidence was sought, but not found, that rate of photosynthesis is any simple function of bicarbonate concentration. In terms of their light intensity curves the three algae show no feature markedly different from those of Chlorella. Limited response of respiration to added organic substrates is considered related to the obligate photo-autotrophic character of the three algae. Attention is directed to Anacystis nidulans which has several features making it particularly useful as an experimental organism for studies on photosynthesis.