title: Application of sequential integration for metabolic engineering of 1,2-propanediol production in yeast.
abstract: The yeast species Saccharomyces cerevisiae was engineered to produce 1,2-propanediol (1,2-PD) using the delta/UB sequential gene integration method. To study the effects of increased copy number, 2 genes (mgs and gldA from Escherichia coli) were sequentially integrated into the chromosomes of S. cerevisiae strains of opposite mating type. The resulting strains (containing 0-3 copies of either mgs or gldA) were mated to create all possible combinations of the 2 genes introduced for 1,2-PD production. Enzyme activities were generally correlated with copy number, although there was greater variation in GldA activity in the diploid cells. The integrated genes were confirmed by Southern blot and 1,2-PD production was analyzed by HPLC. The strain containing 3 copies of mgs and gldA showed the highest level of 1,2-PD; however, 1,2-PD concentration was not clearly related to gene copy number. 1,2-PD production did correlate with Mgs specific activity, and high GldA specific activity was found to be inhibitory.
authors.affiliation: Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA.
authors.forename: Wonkyu
authors.initials: W
authors.lastname: Lee
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Dasilva
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D018628:Gene Dosage / Q000235:genetics*; D005818:Genetic Engineering / Q000379:methods; D019946:Propylene Glycol / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; C109038:GldA protein, bacteria; D019946:Propylene Glycol