title: Improved glutathione production by gene expression in Pichia pastoris.
abstract: To utilize Pichia pastoris to produce glutathione, an intracellular expression vector harboring two genes (gsh1 and gsh2) from Saccharomyces cerevisiae encoding enzymes involved in glutathione synthesis and regulated by the glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter was transformed into P. pastoris GS115. Through Zeocin resistance and expression screening, a transformant that had higher glutathione yield (217 mg/L) in flask culture than the host strain was obtained. In fed-batch culture process, this recombinant strain displayed high activity for converting precursor amino acids into glutathione. The glutathione yield and biomass achieved 4.15 g/L and 98.15 g (dry cell weight, DCW)/L, respectively, after 50 h fermentation combined with addition of three amino acids (15 mmol/L glutamic acid, 15 mmol/L cysteine, and 15 mmol/L glycine).
authors.affiliation: Department of Biochemistry, Shanghai Institute of Pharmaceutical Industry, 200040 Shanghai, People's Republic of China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Fei
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Shaoxin
authors.initials: S
authors.lastname: Chen
mesh_terms: D001483:Base Sequence; D019149:Bioreactors / Q000382:microbiology; D017931:DNA Primers / Q000235:genetics; D015870:Gene Expression; D005818:Genetic Engineering; D005822:Genetic Vectors; D005721:Glutamate-Cysteine Ligase / Q000235:genetics / Q000378:metabolism; D005978:Glutathione / Q000096:biosynthesis*; D010843:Pichia / Q000235:genetics* / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D017931:DNA Primers; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C490862:GSH1 protein, S cerevisiae; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione