title: High level expression of recombinant BoNT/A-Hc by high cell density cultivation of Escherichia coli.
abstract: The carboxylic domain of the Clostridium botulinum neurotoxin heavy chain (BoNT/A-HC), which has been reported as a vaccine candidate, contains the principle protective antigenic determinants. In this study, the high level expression of the BoNT/A-Hc was achieved by high cell density cultivation of recombinant Escherichia coli in a 2-l batch stirred-tank bioreactor. In order to maximize protein expression, post-induction time and IPTG inducer concentration were optimized by the Taguchi statistical design method. Results showed that the middle of the logarithmic phase and an IPTG concentration of 1 mM presented the optimum conditions for the maximum expression of BoNT/A-HC. High cell density cultivation was subsequently carried out as an effective strategy for the high level expression of recombinant BoNT/A-Hc. Consequently, soluble BoNT/A-Hc was produced at the maximum level of 486 mg l(-1), at 3 h post-induction, which was approximately 9.3 and 7.8 times higher than the levels produced by the shake flask and batch culturing methods, respectively.
authors.affiliation: Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Kheirollah
authors.initials: K
authors.lastname: Yari
authors.forename: Seyed Safa-Ali
authors.initials: SS
authors.lastname: Fatemi
authors.forename: Mahmood
authors.initials: M
authors.lastname: Tavallaei
mesh_terms: D019149:Bioreactors; D019274:Botulinum Toxins, Type A / Q000096:biosynthesis* / Q000235:genetics; D003014:Clostridium botulinum / Q000201:enzymology / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics; D014121:Toxoids / Q000096:biosynthesis / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D014121:Toxoids; D019274:Botulinum Toxins, Type A; C545476:incobotulinumtoxinA