Used Methods of Cell Disruption

Resume of cell disruption

With the widespread use of recombinant DNA technology, biotechnology has had a qualitative leap. Many genetically engineered products are intracellular substances, so we must crush the cell walls to release products and in that way, we can make further extraction. Therefore, cell disruption is the key for intracellular substances extraction. And the way of disruption will effect the quantity, quality and cost of extractive. Several used methods of cell disruption in recent years are as follows:

1. High-pressure homogenization

High-pressure homogenizer consists of high-pressure pump and homogenate room. American Microfluidics and ATS Company both have this product.

Operation principle: Cell experiences high-speed shear, crash and the change from high-pressure to ordinary pressure to realize cell disruption.

Problems: This method is not suitable for blob-like and threadlike fungus which easily makes blocking, little gram-positive bacterium and some subcellular organelles because they are hard and they will damage the valve of homogenizer.

2. High-speed bead grinding

The equipment is beads mill. Swiss WBC Company and Germen Siemens Company both manufacture various models of beads mill.

Operation principle: Under the action of mix slurry, microbial cells suspension and tiny abrasive fully mix. Beads and cells experience shear, crash each other to realize cell disruption and release inclusion. With the help of bead wave separator, beads stay in crushing chamber and serous fluid flows out to realize continuous operation. In the course of disruption, the heat will be taken away by cooling fluid in jacket.

Problems: Numerous operating parameters; In general, you must estimate with your experience; The liquid loss between beads and beads is about 30 percent.

3. Ultrasonic disruption
Ultrasonic wave more than 15-20KHz can conduct cell disruption in high strength input of sound energy.

Operation principle: It is may linked with shock wave and shear force which are caused by cavitation phenomenon. The efficiency of ultrasonic disruption will be influenced by audio frequency, sound energy, processing time, cell concentration and type.

Problems: Ultrasonic disruption is common in laboratory scale. Operation is simple and liquid loss is small when dealing a small quantity of samples. But, chemical free gene cluster which is produced by ultrasonic wave can make some sensitive active substance degenerate. And it is difficult for large capacity device of sound energy transfer and heat dissipation. 

4. Enzyme solution

It is the method that using bio-enzyme to dissolve cell wall and cell membrane. Commonly used solvent are Lysozyme beta 1.3-glucan enzymes, protease, ect.

Problems: It will easily result product inhibition and this is may an important reason for low release rate of intracellular substances. Further more, the price of solvent is high, which limits large-scale use. If recover solvent, will increase  process of separation and purification.Otherwise, enzyme solution’s generality is not good and different microorganisms need different enzymes.

5. Chemosmosis method
Some organic solvents (such as benzenes, methybenzenes), antibiotics, surfactants, metal chelators, denaturants and other chemical medicine can change the permeability of cell wall and cell membrane to make inner substance flow out selectively.

Operation principle: Chemosmosis is depend on the types of reagents and construction of cell wall and cell membrane.

Problems: Long time, low efficiency; Chemical reagent’s toxicity is strong and it is poisonous for products; For further separation, you must remove those reagents by dialysis and other ways; Its generality is not good: some reagents can only function in certain types of microbial cells.