Directed evolution and immobilization of new lipase Lip 906

Abstract

In this experimental study, a new lipase named Lip 906 was screened out from a metagenomic library in the laboratory. To improve the stability of the enzyme and develop and apply it as soon as possible, we adopted directed evolution and immobilization methods. A random mutation library was constructed by error-prone PCR and finally, a mutant lipase Lip 5-D with increased enzyme activity was screened out and immobilized. The activity of the mutant enzyme Lip 5-D was improved by 4 times compared with the wild-type lipase Lip 906. The optimal reaction temperature rose by 4 °C, and by 3 °C after immobilization. The optimal reaction pH increased from 7.8 to 7.5. Both temperature stability and pH stability were improved. The mutant enzyme Lip 5-D can maintain about 70% of the relative activity after incubation at 65 °C for 2 h, and it can keep 60% at pH 3-10. Error-prone PCR and immobilization improve the catalytic activity and stability of the enzyme, and promote its development and application in many industries.