title: [The influences of lactose as an inducer on the expression of the recombinant proteins in Escherichia coli BL21 (DE3)].
abstract: The possibility of using lactose as an inducer to substitute the common inducer IPTG in the fermentation process of the recombinant microorganism was deeply investigated. The influences of culture conditions such as lactose concentration, growth medium composition, the point of induction and the duration of the induction phase on the expression of the recombinant protein were analyzed and studied in detail. In the following experiments, lactose was then used in the high cell density culture process of E. coli BL21 (DE3)(pFu). The final cell density (OD600) was over 40. The expression level of recombinant protein was about 15% of the total cellular protein. Both the culture density and foreign protein expression level were lower than those induced by IPTG. However, because of the potential toxicity to human beings and the high cost of IPTG, the use of lactose might provide an alternative means of inducing foreign protein expression. This would be more attractive in industrial scale productions of recombinant proteins. The results confirmed that lactose could be used as an inducer in the fermentation process.
authors.affiliation: Shanghai Research Center of Biotechnology, Chinese Academy of Sciences.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: X M
authors.initials: XM
authors.lastname: Qu
authors.forename: S L
authors.initials: SL
authors.lastname: Yang
mesh_terms: D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000235:genetics*; D005285:Fermentation; D007785:Lactose / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000096:biosynthesis*
chemical_list: D011994:Recombinant Proteins; D007785:Lactose