title: Effect of inducers on the production of 5-aminolevulinic acid by recombinant Escherichia coli.
abstract: Aminolevulinic acid (ALA) was produced by recombinant Escherichia coli BL21(DE3) (pET28-A.R-hemA) harboring the ALA synthase gene (hemA) from Agrobacterium radiobacter zju-0121. The effects of inducers on the ALA synthase activity and ALA productivity were evaluated. The results indicated that a low isopropyl-beta-D-thiogalactoside (IPTG) concentration (0.05 mmol/L) was favorable for high expression of ALA synthase, which resulted in higher ALA productivity. For metabolic engineering applications, lactose was a better substitute of IPTG for active enzyme expression. When lactose concentration was 5 mmol/L, the specific ALA synthase activity and ALA productivity reached 16.7 nmol/(min . mg of protein) and 1.15 g/L, respectively, which were about 15% and 43% higher than those induced by IPTG.
authors.affiliation: Institute of Bioengineering, College of Materials Science and Chemical Engineering, Zhejiang University, Hangzhou, P. R. China.
authors.forename: Liu
authors.initials: L
authors.lastname: Xiaoxia
authors.forename: Lin
authors.initials: L
authors.lastname: Jianping
authors.forename: Cen
authors.initials: C
authors.lastname: Peilin
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000235:genetics / Q000378:metabolism; D000622:Aminolevulinic Acid / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D007785:Lactose / Q000378:metabolism / Q000494:pharmacology
chemical_list: D007544:Isopropyl Thiogalactoside; D000622:Aminolevulinic Acid; D000624:5-Aminolevulinate Synthetase; D007785:Lactose