What is gram negative bactria?

Answer 1

Christian Gram divided the bacteria into 2 types basing on the cell wall composition-Gram negative bacteria and Gram positive bacteria.

Gram negative bacteria have low content of peptidoglycan in their cell wall and high content of lipopolysaccharides.Gram negative bacteria have the outermembrane.Outermembrane can be divided into 3 parts--lipidA,O side chains and Lipoproteins.

Lipid A is responsible for endotoxins[the pathogenecity of Gram negative bacteria is due to lipid A

O side chains are the O antigens [the antibodies of the host recognizes the bacteria with the help of O antigens.

Lipopolysaccharides--present in much higher levels in gram negative bacteria than in gram positive bacteria.The lipoproteins are attached to the polysaccharide backboneand these are called as Braun's lipoproteins.

The outer membrane is more permeable than the plasmamembrane and this nature comes from porins,which help in the transport of fluids.

Examples of Gram negative bacteria include:E.coli,Pseudomonas,Salmonella etc

Answer 2

Gram-negative bacteria are a type of bacteria that do not retain the crystal violet stain used in the Gram staining method, appearing pink or red under a microscope. They have a more complex cell wall structure compared to gram-positive bacteria, with an outer membrane containing lipopolysaccharides that can trigger immune responses. Gram-negative bacteria include many pathogenic species such as Escherichia coli and Pseudomonas aeruginosa.

Answer 3

Gram negative bacterium are bacterium that do not hold the dye used to to identify them as gram positive bacterium.