Difference Between Gram Positive and Gram Negative Cell Wall

Cell walls of gram-positive bacteria are thick and predominantly made of peptidoglycan. In the cell wall of gram-positive bacteria, long chains of sugars and amino acids make up the complex chemical known as peptidoglycan, which supports the bacterial cell wall structurally. Whereas, Gram-negative bacteria have a multilayered cell wall that is a complex construction. The outer membrane, of Gram-negative bacteria, is composed of proteins and lipopolysaccharides (LPS), which is the outermost layer.

Feature of Gram-Positive Cell Wall

• Thick peptidoglycan layer: Outside of the cytoplasmic membrane, gram-positive bacteria have a thick peptidoglycan layer. The cell’s structural support and defense are provided by this peptidoglycan layer.
• Teichoic acids are polymers made of glycerol, ribitol, or glycol that are covalently attached to the peptidoglycan layer in gram-positive bacteria. Teichoic acids are involved in the preservation of cell structure, cell division, and antibiotic resistance.
• Outside of the peptidoglycan layer, Gram-positive bacteria do not possess an outer membrane, in contrast to Gram-negative bacteria. Instead, a layer of proteins and lipids covers the peptidoglycan layer.
• Susceptibility to specific antibiotics: Due to the thick peptidoglycan coating, Gram-positive bacteria are vulnerable to drugs like penicillin and cephalosporins that attack this structure.

Feature of Gram-Negative Cell Wall

Some significant aspects of the Gram-negative cell wall, which is a distinguishing trait of some species of bacteria, include:

• Thin peptidoglycan layer: In comparison to Gram-positive bacteria, gram-negative bacteria have a thinner peptidoglycan layer. The periplasmic space, which is the area between the outer and inner membranes, is where the peptidoglycan layer is found.
• Lipopolysaccharides (LPS) and proteins make up the outer membrane of gram-negative bacteria. This outer membrane serves as a defense against harmful environmental elements and hinders the entry of antimicrobial agents into the bacterial cell.
• Lipopolysaccharides (LPS): Lipid A, core polysaccharide, and O-antigen make up the LPS layer of the outer membrane. The host immune system recognizes lipid A as an endotoxin and it might result in fever, inflammation, and other infection-related symptoms.
• Porins: The outer membrane of Gram-negative bacteria contains porins, which are proteins that form channels that allow the flow of tiny molecules, such as nutrients, into the cell.

Difference Between Gram-Positive and Gram-Negative Cell Walls

Parameters	Gram-Positive Cell Wall	Gram-Negative Cell Wall
Thickness of the peptidoglycan layer	It is too much thick	It is thin.
Availability  of outer membrane	The outer membrane does not present.	Here outer membrane is present.
Presence of Lipid content	Here teichoic acid and lipoteichoic acid are present.	Here lipopolysaccharide (LPS), lipoprotein, and phospholipids are present.
Presence of Porin proteins	It is not present.	It is present in the outer membrane.
Susceptibility to antibiotics	This is  more susceptible due to the thicker peptidoglycan layer	This is less susceptible because of the outer membrane and efflux pumps.
Toxicity	Here toxicity is  less	Here toxicity is High
Outer membrane components	Does not have any outer membrane	These are some components that are present in the outer membranes such as Lipopolysaccharide (LPS), lipoprotein, and phospholipids
Presence of periplasmic space	very small or negligible  periplasmic space is available	Large periplasmic space is available
Ability to form endospores	There are only some species can form endospores because it is highly resistant structures.	Here can not be formed.
Ability to lyse in a hypertonic environment	It is susceptible to lysis	It is resistant to lysis
Presence of flagella	It may have peritrichous or polar flagella	It may also have peritrichous or polar flagella