Question

What would happen if a gram-positive bacterium was placed in very salty water? Why?

Answer 1

Nothing will happen because:

• Gram-positive bacteria lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in the Gram-negatives.
• The additional component in a gram positive cell wall is teichoic acid, a glycopolymer, which is embedded within the peptidoglycan layers.
• Teichoic acid is believed to play several important roles for the cell, such as generation of the net negative charge of the cell, which is essential for development of a proton motive force.
• Teichoic acid contributes to the overall rigidity of the cell wall, which is important for the maintenance of the cell shape, particularly in rod-shaped organisms.
• Teichoic acids appear to play a role in resistance to adverse conditions such as high temperatures and high salt concentrations, as well as to β-lactam antibiotics.