Describe the advantages of using an engineered strain of E c

Describe the advantages of using an engineered strain of E. coli to express Taq DNA polymerase rather than purifying Taq DNA polymerase from a large culture of Thermus aquaticus.

Solution

Isolation and purification of Taq DNA polymerase from a large culture of Thermus aquaticus is highly expensive and time consuming process. Moreover, Thermus aquaticus is an extremophile living in high temperatures and it is not easy to collect sample from extreme locations and cultivate them under extreme conditions in laboratory. It is easier to insert the Taq polymerase expressing gene into E. coli to produce large quantities of enzyme by minimum efforts through genetic engineering. The process is as follows:

1. Gene encoding Taq polymerase is identified.

2. The DNA is cut with a specific restriction endonuclease. Same restriction enzyme is used to cut the plasmid.

3. The gene of inserted into plasmid and ligated with DNA ligase.

4. The plasmid is introduced into E. coli cells and transfoemd.

5. The transformed cells are screened for presence of Taq polymerase gene.

6. The gene from E. coli is amplified through PCR.