Bacterial Cell Wall Structure and Staining Characteristics

Bacteria are single-celled organisms that can thrive in a variety of environments, including extreme conditions. They possess distinct structural features that make them well-adapted to their surroundings.

One of the most notable features of bacteria is their cell wall, which provides structural support and protection. The composition of the cell wall varies among different bacterial species, which can be classified broadly into two groups based on this composition: Gram-positive and Gram-negative bacteria. Understanding the differences between these groups is essential for microbiology.

Gram-positive bacteria have a thick peptidoglycan layer that retains the crystal violet stain used in the Gram staining procedure. As a result, they appear purple under a microscope. In contrast, Gram-negative bacteria have a thinner peptidoglycan layer and an outer membrane containing lipopolysaccharides, which causes them to appear pink after staining.