title: Improvement of betulinic acid biosynthesis in yeast employing multiple strategies.
abstract: Betulinic acid (BA) is a lupane-type triterpene which has been considered as a promising agent to cure melanoma with no side effects. Considering that BA is naturally produced in small quantities in plants, we previously reported the success in engineering its production in yeast. In the present study, we attempted to improve BA biosynthesis in yeast by the use of different strategies.
  
  
  
  We first isolated a gene encoding a lupeol C-28 oxidase (LO) from Betula platyphylla (designated as BPLO). BPLO showed a higher activity in BA biosynthesis compared to the previously reported LOs. In addition, two yeast platforms were compared for engineering the production of BA, which demonstrated that the WAT11 strain was better to host BA pathway than the CEN.PK strain. Based on the WAT11-chassiss, the Gal80p mutant was further constructed. The mutant produced 0.16 mg/L/OD600 of BA, which was 2.2 fold of that produced by the wild type strain (0.07 mg/L/OD600).
  
  
  
  This study reported our efforts to improve BA production in yeast employing multiple strategies, which included the identification of a novel LO enzyme with a higher activity in BA biosynthesis, the evaluation of two yeast strains for hosting the BA pathway, and the up-regulation of the expression of the BA pathway genes by managing yeast GAL gene regulon circuit.
authors.affiliation: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhou
authors.affiliation: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.
authors.forename: Changfu
authors.initials: C
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China. zhangys@wbgcas.cn.
authors.forename: Yansheng
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D005690:Galactose / Q000235:genetics* / Q000378:metabolism; D024861:Genetic Enhancement / Q000379:methods*; D005947:Glucose / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*; D053978:Pentacyclic Triterpenes; D012441:Saccharomyces cerevisiae / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D013045:Species Specificity; D014315:Triterpenes / Q000302:isolation & purification / Q000378:metabolism*; D000094062:Betulinic Acid
chemical_list: D053978:Pentacyclic Triterpenes; D029701:Saccharomyces cerevisiae Proteins; D014315:Triterpenes; D005947:Glucose; D005690:Galactose; D000094062:Betulinic Acid
keywords: Betulin; Betulinic acid; Biosynthesis; Saccharomyces cerevisiae