Cell disruption is an important step in downstream processing and can be achieved through physical, mechanical, or chemical/enzymatic methods. Physical methods include blending, ultrasonication, and freezing and thawing, which use shear forces or cavitation to break open cells. Mechanical methods like French press cells use high pressure to burst cells as they pass through a small orifice. Chemical/enzymatic methods employ enzymes, detergents, osmotic shock, or other chemicals to disrupt cell membranes. Lysozyme is commonly used to break open bacterial cells while zymolyase and lyticase disrupt yeast.

1. UNIT-II
DOWN STREAM PROCESSING

2. CELL DISRUPTION METHOD-
• Physical.
• Mechanical process.
• Alkalis.

3. PHYSICAL-
• Blenders.
• Ultrasonication.
• Freezing thawing.
Blenders-
• This method is ideal for disrupting mammalian or plant tissue by
shear force.
• Tissue are cut in to the small pieces &blended in the presence of
the buffer for about 1 minute to disrupt the tissue.
• Centrifugation is done to remove the cell debris.
• This method is appropriate for the bacterial &yeast cell.
• Cells are trapped b/w chelating beads & are disrupted physically.

4. Grinding mill abrasives-
• Grinding in the mortar in the presence of the san alumina
with small amount of the buffer.
Ultrasonication-
• This method is ideal for the suspension of cultured cell.
• Cell suspension is put on the sonicator probe& high frequency
sound wave for about 20 kHz.
• The sound wave causes the disruption of the cell by shear forces
&cavitation.
• Gas bubble form under the pressure releases the shock wave which
disrupts the plasma membrane.
• This method is suitable for the small volume 50 -100 mtr/cm3.

5. Mechanical method-
French pressure cell-
• It is used in the biological system to extract homogenate
of cell suspension microbial cell &chloroplast.
• It was invented by the Charles Stacy French.
• All cell suspension is passed by the hydrolytic piston
pump under high pressure through the small orifice
pressure is rapidly dropped.
• Compressed cell expend &effectively burst.
• All the cells are under carefully managed under the control
condition & cell release the protein from the periplasmic
space.

6. CHEMICAL OR ENZYMETIC
METHOD-
• Salt.
• Detergent.
• Enzyme.
• Osmotic shock.
Detergent-
• Detergents have been used to disrupt the
cell membrane &extract the lipoprotein.
• It includes the salt such as chelate
nonionic detergent like SDS,CTAB.

7. Enzyme-
• Enzyme lysozyme is isolated from the hen egg
white cleaves the peptidoglycan layer of the
bacteria.
• G- Bacteria can be similarly disrupted by the
lysozyme enzyme.
• The two most commonly enzyme for the yeast
zymolyase &lyticase .
• It consist beta 1.3 gluconase activity.
• Kitinase is used for disrupt filament of the fungi.

8. Polyvenyl pyrolidone-
• PVP is adding to the extraction of the buffer for plant tissue
contain the considerable amount of the phenolic compound.
• This enzyme bind to the co- valent forces including the H
bond, ionic bond hydrophobic bond causing the protein
precipitation.
• This phenolic group is easily oxidized by the phenol oxidase to
form the Quinone which is highly reactive can combined with
reactive group.
• In soluble PVP is added to extraction buffer to absorb the
phenolic compound.
Na –Azide-
• It is added in the buffer for the long period of the period of
the time.
• It acts as the antifungal &antibacterial agent.