title: [Optimization of synthetic pathway and fermentation process of yeast cell factories for production of oleanoic acid].
abstract: OBJECTIVE
  To optimize the synthetic pathway and fermentation process of yeast cell factories for production of oleanoic acid.
  
  
  METHODS
  Using the DNA assembler method, one copy of Glycyrrhiza glabra beta-amyrin synthase (GgbAS), Medicago truncatula oleanolic acid synthase (MtOAS) and Arabidopsis thaliana cytochrome P450 reductase 1 (AtCPR1) genes were introduced into Saccharomyces cerevisiae strain BY-OA, resulting in strain BY-20A. YPD medium with different glucose concentration were then used to cultivate strain BY-2OA.
  
  
  RESULTS
  Increasing gene copies of GgbAS, MtOAS and AtCPR1 resulted in increased beta-amyrin and oleanolic acid production. The strain BY-2OA produced 136.5 mg x L(-1) beta-amyrin and 92.5 mg x L(-1) oleanolic acid, which were 54% and 30% higher than the parent strain BY-OA. Finally, the titer of oleanolic acid increased to 165.7 mg x L(-1) when cultivated in YPD medium with 40 mg x L(-1) glucose.
  
  
  CONCLUSIONS
  Production of oleanoic acid increased significantly in the yeast strain BY-2OA, which can provide the basis for creating an alternative way for production of oleanoic acid in place of extraction from plant sources.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Bei-Bei
authors.initials: BB
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Ming-Yu
authors.initials: MY
authors.lastname: Shi
authors.forename: Dong-Guang
authors.initials: DG
authors.lastname: Xiao
authors.forename: Lu-Qi
authors.initials: LQ
authors.lastname: Huang
authors.forename: Zhu-Bo
authors.initials: ZB
authors.lastname: Dai
authors.forename: Xue-Li
authors.initials: XL
authors.lastname: Zhang
mesh_terms: D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005285:Fermentation; D005947:Glucose / Q000494:pharmacology; D009828:Oleanolic Acid / Q000096:biosynthesis*; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*
chemical_list: D009828:Oleanolic Acid; D005947:Glucose