Cyanobacteria are halotolerant: They are capable of accumulating
low molecular weight halides intracellularly in response to a high
osmotic pressure. They can be cultivated in a medium containing
0.11M NaCl, or in a medium containing 0.49 M NaCl and 0.01 M CaCl2.
When cells grown in more saline medium are transferred to the fresh
water, their cell-wall cracks and they become permeable, i.e., the
intracellular carbohydrate and amino acid are released into the
medium within 2 min. Estimate the osmotic pressure difference which
makes the membranes of the cyanobacteria permeable.