title: Heterologous gene expression in bacterial systems under reduced oxygen tensions. Small-scale optimization precedes industrial fermentation.
abstract: The expression of heterologous fusion proteins from the anaerobically inducible Escherichia coli nitrite reductase nirB promoter has been described using a number of different industrial regimes, but which have proved impractical for scaling down to suit primary research purposes. This paper describes the novel application of microbiological gas sachets generating anaerobic and microaerophilic environments to evaluate the inducible expression under the influence of nirB of heterologous proteins by attenuated vaccine strains of Salmonella typhimurium. The conditions of reduced oxygen tension model those found in lymphoid organs colonized by Salmonella in vivo and so can be used to optimize the vaccine dose prior to administration. Modeling in vivo promoter inducibility to monitor the stability of a plasmid within attenuated vaccine strains of bacteria offers an attractive alternative to antibiotic resistance, which is not permitted for clinical use in humans. This technological advance may be utilized to optimize heterologous gene expression in any microaerophilic bacterial system as a pilot, prior to production-scale applications.
authors.affiliation: School of Biology, University of Leeds, Lnited Kingdom.
authors.forename: A W
authors.initials: AW
authors.lastname: Taylor-Robinson
authors.forename: K G
authors.initials: KG
authors.lastname: Heal
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D000941:Antigens / Q000008:administration & dosage / Q000235:genetics; D000953:Antigens, Protozoan / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005285:Fermentation; D015870:Gene Expression; D009572:Nitrite Reductases; D010100:Oxygen / Q000008:administration & dosage*; D010446:Peptide Fragments / Q000235:genetics; D010963:Plasmodium falciparum / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D011993:Recombinant Fusion Proteins; D012486:Salmonella typhimurium / Q000235:genetics*; D013744:Tetanus Toxin / Q000235:genetics; D014614:Vaccines, Synthetic / Q000235:genetics
chemical_list: D000941:Antigens; D000953:Antigens, Protozoan; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D010446:Peptide Fragments; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D013744:Tetanus Toxin; D014614:Vaccines, Synthetic; C040635:tetanus toxin fragment C; D009572:Nitrite Reductases; C079730:NirB protein, E coli; D010100:Oxygen