title: Higher ploidy in Saccharomyces cerevisiae supports enhanced hepatitis B virus S cloned gene expression at the pilot scale.
abstract: The effect of host strain ploidy on the production of hepatitis B surface antigen (HBsAg) in Saccharomyces cerevisiae was evaluated at the pilot scale (75 L). We found that the accumulation of HBsAg normalized to cell protein was 2-fold higher for the diploid strain compared to its isogenic haploid. No detectable differences in many fermentation parameters were observed (e.g., rate of fermentation, growth rate, final cell yield). However, the enhancement of productivity in the diploid strain appeared to be associated with a slower rate of plasmid shedding (2 microns element) and, thus, a higher average copy number (2-fold at stationary phase) compared to those of the haploid strain.
authors.affiliation: Department of Vaccine Bioprocess R&D, Merck Research Laboratories, West Point, Pennsylvania 19486, USA.
authors.forename: J
authors.initials: J
authors.lastname: Fu
authors.forename: C B
authors.initials: CB
authors.lastname: Parker
authors.forename: P
authors.initials: P
authors.lastname: Burke
authors.forename: L D
authors.initials: LD
authors.lastname: Schultz
authors.forename: D L
authors.initials: DL
authors.lastname: Montgomery
authors.forename: B A
authors.initials: BA
authors.lastname: Arnold
authors.forename: K
authors.initials: K
authors.lastname: McGinnis
mesh_terms: D003001:Cloning, Molecular; D004171:Diploidy; D005285:Fermentation; D015967:Gene Expression Regulation, Viral; D006238:Haploidy; D006514:Hepatitis B Surface Antigens / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D007700:Kinetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism
chemical_list: D006514:Hepatitis B Surface Antigens; D011994:Recombinant Proteins