If the peptidoglycan layer is thin, it's classified as gram negative. A gram-positive bacillus doesn't have an outer cell wall beyond the peptidoglycan membrane. This makes it more absorbent.

Gram-positive bacteria have thick cell walls. A Gram stain test, which involves a chemical dye, stains the bacterium’s cell wall purple. On the other hand, gram-negative bacteria stain pink instead.

Experts divide them into Gram-positive cocci or bacilli, depending on their shape. Gram-negative bacteria have different structures. They have a far thinner layer of peptidoglycan, which is why ...

Gram-positive bacteria can be cocci- (spheres) or bacilli- (rod) shaped, or have branching filaments. Gram-negative bacteria have an outer membrane. However, they have a thinner peptidoglycan cell ...