Bacteria that have no cell wall, L form bacteria, Protoplast, Spheroplasts, gram negative, gram positive bacteria Full notes

Bacteria that have no cell wall:

L Forms:

L-forms are bacteria that have lost the ability to form a complete cell wall.

They were first observed in 1935 at the Lister Institute in Paris, from which they derived their name.

L-form arises from both gram-positive and negative bacteria.

They are growing in the tissue of their animal hosts. Some L-form make partial cell walls

All L-form required a very rich growth medium with high osmolarity.

Protoplast:

The protoplast cell wall remove gram-positive bacteria

The protoplast is osmotically sensitive.

Lysozyme treatment can remove the entire cell wall of a gram-positive bacteria, resulting in an osmotically cell wall called a Protoplast.

Protoplast always takes the form of a sphere because of the internal osmotic pressure pushes equally in all directions.

Protoplast looks a rigid cell wall, Protoplasts are very fragile and must be maintained in isotonic the solution to prevent them from lysing.

Spheroplasts:

The Spheroplast remove the cell wall of gram-negative bacteria

Gram-negative bacteria are first treated with a chelating agent such as EDTA(Ethylene diamine tetraacetic acid)

In gram-negative cell walls to destroy their outer membrane lysozyme attack the peptidoglycan layer.

Due to this, they lose their shape and become spherical and the peptidoglycan layer is digested away so due to this called Spheroplast.

For notes on the cell wall  click here