title: Controlled fed-batch fermentation of recombinant Saccharomyces cerevisiae to produce hepatitis B surface antigen.
abstract: We have performed controlled fed-batch fermentation experiments to compare the production level of hepatitis B surface antigen (HBsAg) by recombinant yeast Saccharomyces cerevisiae strains (YNN27/pYBH-1, YNN27/ p2micro-S11, YNN27/pDCB-S2) containing plasmid vector with alcohol dehydrogenase (ADH1), acid phosphatase (PHO5), and glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter, respectively. Yeast cell concentrations of 15-35 g dry cell weight/L were obtained. By limiting phosphorous concentration, HBsAg expression level for the YNN27/p2micro-S11 strain with inducible PHO5 promoter reached 0.2-0.3 mg/L. By controlling nutrient addition rate and dissolved oxygen concentration, HBsAg concentrations of 3-10 mg/L were achieved in 60-70 h fermentation using the YNN27/pDCB-S2 strain with the constitutive GPD promoter.
authors.affiliation: Process Development Department, Development Center for Biotechnology, 81 Chang Hsing Street, Taipei, Taiwan, Republic of China.
authors.forename: J H
authors.initials: JH
authors.lastname: Hsieh
authors.forename: K Y
authors.initials: KY
authors.lastname: Shih
authors.forename: H F
authors.initials: HF
authors.lastname: Kung
authors.forename: M
authors.initials: M
authors.lastname: Shiang
authors.forename: L Y
authors.initials: LY
authors.lastname: Lee
authors.forename: M H
authors.initials: MH
authors.lastname: Meng
authors.forename: C C
authors.initials: CC
authors.lastname: Chang
authors.forename: H M
authors.initials: HM
authors.lastname: Lin
authors.forename: S C
authors.initials: SC
authors.lastname: Shih
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
authors.forename: T Y
authors.initials: TY
authors.lastname: Chow
authors.forename: T Y
authors.initials: TY
authors.lastname: Feng
authors.forename: T T
authors.initials: TT
authors.lastname: Kuo
authors.forename: K B
authors.initials: KB
authors.lastname: Choo