1. The fluid-filled space between the inner and outer membranes of gram-negative bacteria.
Usage: technical; microbiology

Examples

• The periplasm of gram-negative bacteria contains enzymes and transport proteins.
• Antibiotics can target proteins located in the periplasm.
• The periplasm acts as a buffer zone between the cell wall and the cytoplasm.
• Researchers studied how toxins cross the periplasm to reach the inner membrane.
• The periplasm is absent in gram-positive bacteria, which have only a single membrane.