[Morphologic heterogeneity under different conditions of living and destruction in Anabaena variabilis cyanobacteria]

The proportion between various morphological forms of the cyanobacterium Anabaena variabilis was studied under different conditions of its growth and destruction. When the cells lost viability at the stationary phase of cultural growth under the optimal conditions of illumination (1500--2000 lx), in the dark or when nitrogen was deficient, the filaments became shorter (4 to 2.2 cells per filament on the average), the cells larger, 4.5x6 microns). Under the conditions of nitrogen deficiency, the content of phycocyanin sharply decreased as well as that of chlorophyll. "Aging" under the conditions of optimal illumination was accompanied with "weighting" of the cells at the prolonged stationary phase and a gradual decrease in the content of phycocyanin and chlorophyll. When the cells were exhausted in the dark, the content of protein, RNA and phycocyanin decreased while that of chlorphyll hardly changed for a considerably long period of time. The most versatile morphological heterogeneity, when the cells were rapidly destroyed under the conditions of high light intensity, was as follows: both larger and more spherical as well as smaller and longer than in the control cells was found and catenuate cells were detected. The colour of the culture was light-brown or blue. When grown in a medium containing aspartic acid, the culture consisted of long filaments (ca. 18 cells per fragment instead of 4 cells in the control).