Spheroplast

Spheroplasts are cells that have had their cell wall partially removed, typically by enzymatic treatment or mechanical disruption. This process is often used in microbiology and molecular biology to study the cell membrane and internal components of the cell. Spheroplasts are particularly useful in the study of bacteria and yeast cells, where the rigid cell wall can impede access to the cell's interior.

Formation of Spheroplasts

Spheroplasts are formed by treating cells with enzymes such as lysozyme or zymolyase, which degrade the cell wall. In the case of bacterial cells, lysozyme is commonly used to break down the peptidoglycan layer of the cell wall. For yeast cells, zymolyase is used to digest the glucan and mannan components of the cell wall.

The process of spheroplast formation typically involves the following steps:

1. Enzymatic Treatment: The cells are incubated with an enzyme solution that specifically targets the cell wall components.
2. Osmotic Stabilization: To prevent the cells from lysing due to osmotic pressure, they are suspended in an isotonic solution, often containing a high concentration of a solute such as sucrose or sorbitol.
3. Partial Removal of the Cell Wall: The enzymatic action results in the partial removal of the cell wall, leaving the cell membrane intact.

Applications of Spheroplasts

Spheroplasts are used in various applications, including:

• Genetic Transformation: Spheroplasts are more permeable to DNA and other macromolecules, making them ideal for transformation experiments where foreign DNA is introduced into the cell.
• Membrane Studies: With the cell wall removed, researchers can study the properties and functions of the cell membrane more easily.
• Drug Testing: Spheroplasts can be used to test the effects of antibiotics and other drugs on the cell membrane.

Differences Between Spheroplasts and Protoplasts

While both spheroplasts and protoplasts involve the removal of the cell wall, there is a key difference:

• Spheroplasts: The cell wall is only partially removed, and some remnants of the wall may remain attached to the cell membrane.
• Protoplasts: The cell wall is completely removed, leaving only the cell membrane.

Also see

• Protoplast
• Cell wall
• Lysozyme
• Zymolyase
• Transformation (genetics)

Cell biology