title: Co-expression of bacterial hemoglobin overrides high glucose-induced repression of foreign protein expression in Escherichia coli W3110.
abstract: Co-expression of Vitreoscilla hemoglobin (VHb) can enhance production of foreign proteins in several microorganisms, including Escherichia coli. Production of foreign proteins [green fluorescent protein (GFP) and organophosphorous hydrolase (OPH)] has been examined in two typical industrial E. coli strains, W3110 (a K12 derivative) and BL21 (a B derivative). In particular, we investigated the effects of VHb co-expression and media glucose concentration on target protein production. We employed the nar O(2)-dependent promoter for self-tuning of VHb expression based on the natural changes in dissolved O(2) levels over the duration of culture. Foreign protein production in strain BL21 was decreased by a high glucose concentration but co-expression of VHb had no effect on this. In contrast, co-expression of VHb in strain W3110 overrode the glucose-induced repression and resulted in steady expression of foreign proteins.
authors.affiliation: Department of Chemical Engineering & Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: Yeon Kyu
authors.initials: YK
authors.lastname: Kim
authors.forename: Dong Gyun
authors.initials: DG
authors.lastname: Kang
authors.forename: Suk-Soon
authors.initials: SS
authors.lastname: Choi
authors.forename: Ji Hyeon
authors.initials: JH
authors.lastname: Kim
authors.forename: Jae Chun
authors.initials: JC
authors.lastname: Chung
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Cha
mesh_terms: D043303:Aryldialkylphosphatase / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis*; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D002478:Cells, Cultured; D004926:Escherichia coli / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006454:Hemoglobins / Q000096:biosynthesis*; D010100:Oxygen / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic; D054793:Truncated Hemoglobins
chemical_list: D001426:Bacterial Proteins; D006454:Hemoglobins; D011994:Recombinant Proteins; D054793:Truncated Hemoglobins; C082613:hemoglobin protein, Vitreoscilla; D049452:Green Fluorescent Proteins; D043303:Aryldialkylphosphatase; D005947:Glucose; D010100:Oxygen