RELEASE OF GLUCOSYLGLYCEROL FROM THE CYANOBACTERIUM SYNECHOCYSTIS SPEC SAG-92.79 BY HYPOOSMOTIC SHOCK

When cells of Synechocystis, adapted to 684 mmol/l NaCl, were exposed to hypoosmotic shock by reducing NaCl concentration to more than 250 mmol/l, significant amounts of organic material were liberated which could be increased by increasing shock strength. After maximal hypoosmotic shock (684 mmol/l→ 2 mmol/l NaCl) 40-50% of photosynthetically labelled organic material occurred in the surrounding medium. The main compound exudates was the osmoprotective compound glucosylglycerol. Minor exudates were amino acids, organic acids and carbohydrates. In contrast a hyperosmotic shock (2 mmol/l→684 mmol/l NaCl) liberated only one fourth of the amount liberated by a hypoosmotic shock. © 1990 Springer-Verlag.