W. Bilger et al., PHOTOSYNTHETIC ACTIVITY OF 2 DEVELOPMENTAL STAGES OF A NOSTOC STRAIN (CYANOBACTERIA) ISOLATED FROM GEOSIPHON-PYRIFORME (MYCOTA), Journal of phycology, 30(2), 1994, pp. 225-230
Sessile colonies and motile hormogonia, the two main developmental sta
ges in the life cycle of a Nostoc strain isolated from the endocytobio
sis with Geosiphon pyriforme (Kutzing) F. v. Wettstein, were investiga
ted for their photosynthetic competence. Large-scale fractionation of
the two stages is presented. Photosynthetic parameters were assessed b
y measurement of chlorophyll fluorescence and oxygen evolution. Hormog
onia were as photosynthetically competent as the colonial stage. In ad
dition, hormogonia showed an enhanced capability for nonradiative diss
ipation of absorbed light energy, a feature that might be important fo
r their function as propagula. Data for the quantum yield of photosyst
em II of the isolated Nostoc strain were compared to the values determ
ined in situ in G. pyriforme and indicated the possibility of a higher
photosynthetic capacity of the endosymbiotic as compared to the isola
ted cyanobacterium.