Lysis In Cell Wall: 7 Interesting Facts You Should Know

In this post, you will find the information about lysis in cell wall, how can lysis occur in cell wall and more interesting facts.

Lysis in cell wall is way of breaking down the cell wall or cell membrane to release the cell components. Lysis in cell wall can be spontaneous or it can be induced depending upon the surrounding and the organism type.

Can lysis in cell walls occur?

Lysis can also occur in cell wall, only if the peptidoglycan is weaken or some external substance preventing it form cross linking, which ultimately make peptidoglycan weak and thus the cell wall breaks.

This usually happens when bacterial cell is treated with antibiotic like penicillin which act on the cell wall and make cell wall synthesis stop.  This makes the peptidoglycan weak and thus bacterial cell cannot prevent osmotic lysis  and thus bacteria dies.

What is the lysis in cell wall?

The breaking down of the cell membrane of a cell by physical, chemical and biological means is referred to as lysis of  a cell. Lysis can be spontaneous or it can be induced.

A fluid containing lysis of cell is called lysate. In down streaming processes, the cell cultures are subjected to lysis to purify the cell components or to isolate the desired cell product.

What causes lysis to occur?

The main cause of lysis to occur is alteration in the surrounding environment of cell or external pressure or it can be some biologically active substance which interfere with the cell membrane, this is done spontaneously in human body, if a body is encounter by the bacteria, our body cells secretes enzyme called lysozyme which primarily act on cell membrane to dissolve it and disrupts the cell.

A bacteriophage also secretes lytic enzymes to disrupts the bacterial cell. Artificially it is done by giving the bacteria different cell wall inhibiting antibiotics which is also enzyme mediated. These antibiotics work on the bacterial enzyme transpeptidase, antibiotic stops the transpeptidase enzyme to make further synthesis of cell wall. This make the cell wall weak and it cannot prevent the osmotic pressure. Thus the bacterial cell disrupts and dies.

How does the cell wall prevent lysis?

Bacterial cell contains peptidoglycan which helps the bacteria to prevent cell lysis. Peptidoglycan is made by crosslinking of sugars and peptides, this allows the bacteria to tackle the osmotic lysis.

Osmotic lysis occurs in cell when cell is in hypotonic medium where external fluid moves inside the cell due to osmosis, making the cell turgid and bursts. Organisms having cell wall prevent membrane from bursting. The cytolysis is maily occur in protozoa and animals because they lack cell wall.

What happens in a lysis reaction?

There are two methods which are involved in the lysis. These methods are mechanical and non-mechanical. Each method has its unique reaction. Mechanical methods involve High pressure homogenizer and Bead mill. Non mechanical method is further classified into Physical, chemical and biological means.

The mechanical and non-mechanical method and their types are discussed below:

  • High Pressure homogenizer is widely used in the disruption of microbial cultures at large scale. In this technique, the bacterial culture in media is allowed to pass through a opening valve using high pressure. The membrane of bacteria disrupts due to the high shear force, as it compress when entering the opening valve and expands when discharges.
  • Bead mill is another mechanical method widely used in the molecular laboratory. In this method, tiny bead of glass, steel or ceramic is allowed to mix with the cell culture and agitate at high speed. This makes the disruption of cell, when beads collide with cell and cell lyse by shear force release the intracellular components.
  • The size of beads is 0.25-0.5mm. The smaller size of beads are more effective and recommended for lysis of cell.
  • Physical disruption involves the disruption of cell by using external forces like thermal lysis, osmotic disturbance and cavitation.
  • Thermal lysis involves the continuous freezing and thawing of  the culture which causes the ice formation on the cell membrane that gets easily broken. But this process consumes time and cannot be used for the cultures that are sensitive to the temperature.
  • Cavitation is done reducing local pressure that can be executed by increasing the ultrasonic vibration. This will cause the subsequent formation of cavity or bubbles in the cell membrane. When these bubbles collapse, they produce a disturbance wave in the medium, this wave has high energy which is used to disintegrate the cell membrane.
  • Osmotic disturbance allows the cell to burst by creating concentration difference inside and outside the cell. Water will move inside the cell if the salt concentration is lower in the outer medium which makes the cell burst.
  • Chemical methods involves the disruption of cell by using different lysis buffer, which lyse the cell membrane by altering the pH.
  • In alkaline lysis,  buffer mainly consists of SDS (sodium dodecyl sulphate) and sodium hydroxide. OHion from sodium hydroxide reacts with membrane and breaks the bonds making them permeable and SDS dissolves the protein and membrane. The most preferable range of pH for lysis is 11.5 -12.5.
  • Detergent lysis is one the widely used chemical method for lysis in cell wall. Detergent is also called surfactant. As we know the cell membrane is a bi-lipid layer structure consisting of hydrophilic and hydrophobic regions, and detergents are able to disintegrate the lipid-protein, lipid-lipid and protein-protein interactions.
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Cell lysis using detergent to open the cell membrane and release the intracellular components from A Review on Macroscale and Microscale Cell Lysis Methods
  • Biological methods involve the enzymatic reaction which uses different enzymes to lyse the cell membrane. The important enzymes used as tool to lyse the cell are: lysozyme, protease, cellulase, zymolase, chitinase, proteinase K etc.
  • Lysozyme reacts with the cell wall of bacteria and breaks the glycosidic bonds in the peptidoglycan layer.

What is the need for cell lysis?

Cell lysis is an important part of molecular biology that helps to study the different cell structures and their components closely. Cell lysis is mainly employed in molecular diagnosis of pathogen, immunoassays, antidote screening, composition of specific proteins, nucleic acids  and other cell structure. Cell is widely used in the down streaming processes in pharmaceutical industries to purify the desired protein or gene product synthesized inside the cell.

How does cell lysis work?

It is basically the rupture of the cell membrane which makes the release of the cell component or lysate.  This is done spontaneously in human body, if a body is encounter by the bacteria, our body cells secretes enzyme called lysozyme which primarily act on cell membrane to dissolve it and disrupts the cell. A bacteriophage also secretes lytic enzymes to disrupts the bacterial cell.

Artificially it is done by giving the bacteria different cell wall inhibiting antibiotics which is also enzyme mediated. These antibiotics work on the bacterial enzyme transpeptidase, antibiotic stops the transpeptidase enzyme to make further synthesis of cell wall. This make the cell wall weak and it cannot prevent the osmotic pressure.

Conclusion

To wrap up this post, we conclude that lysis can occur in cell membrane and cell wall of the organism. This can be done by spontaneously or it can be induced artificially. There are different methods by which we can induce cell lysis like physical, chemical and biological means. Spontaneously it is done inside the human body and bacteria.

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