Final answer:
A Halophile would find hypotonic conditions most detrimental because they require high salt concentrations and low solute external conditions could cause their cells to burst due to osmotic pressure.
Step-by-step explanation:
The microorganism that would find hypotonic conditions most detrimental is a Halophile. Halophiles are organisms that thrive in environments with high salt concentrations. In a hypotonic environment, where the solute concentration outside the cell is lower than inside, water would rush into the cells of a halophile, potentially causing the cells to swell and burst due to osmotic pressure.