Investigating the induction effect of lactose and IPTG on Interferon β-1b gene expression in Escherichia coli BL21 (DE3)

Aim and Lac promoter, a regulatory gene in Escherichia coli, is a prokaryotic expression system for recombinant Interferon production. This promoter is induced by lactose or IPTG, its chemical analog. In this study, the effect of lactose and IPTG on the expression of gene was compared.
Escherichia coli BL21 (DE3) harboring Interferon β-1b gene were cultured and induced by the addition of IPTG and / or lactose. The yield of produced Interferon protein was measured.
The yield of Interferon β-1b protein increased by using 0.2% lactose and 0.5 mM IPTG simultaneously as inducers in comparison with each inducer alone and it was equal to 34% of the total cell proteins.
In this research, with simultaneous presence of Lactose and IPTG, in comparison with each one of this inducers alon, a higher yield of the interferon beta 1b protein at a lower cost was produced.