Suddenly put E. coli in 20% NaCl solution and distilled water respectively. What will happen?
When E. coli cells put in 20% NaCl solution then it gives hypertonic environment which means concentration of solutes are more on outside of a cell as compared to inside of a cell.
Therefore, E. coli cells lose water to the environment because of movement of water out of the cell to an area of more solute concentration that has 20% NaCl solution.
Distilled water provides hypotonic environment which means there is movement of water into the cell cytoplasm and it causes lysis.
On adding growth nutrients to distilled water make solution an isotonic state. Therefore, E. coli growth will be supported.
But, on adding growth nutrients to 20% NaCl solution then E. coli growth will not supported because cells may be halophilic and may adapted to highly saline conditions for their survival in such an environment.