title: Dynamic control of gene expression in Saccharomyces cerevisiae engineered for the production of plant sesquitepene α-santalene in a fed-batch mode.
abstract: Microbial cells engineered for efficient production of plant sesquiterpenes may allow for sustainable and scalable production of these compounds that can be used as e.g. perfumes and pharmaceuticals. Here, for the first time a Saccharomyces cerevisiae strain capable of producing high levels of α-santalene, the precursor of a commercially interesting compound, was constructed through a rationally designed metabolic engineering approach. Optimal sesquiterpene production was obtained by modulating the expression of one of the key metabolic steps of the mevalonate (MVA) pathway, squalene synthase (Erg9). To couple ERG9 expression to glucose concentration its promoter was replaced by the HXT1 promoter. In a second approach, the HXT2 promoter was used to express an ERG9 antisense construct. Using the HXT1 promoter to control ERG9 expression, it was possible to divert the carbon flux from sterol synthesis towards α-santalene improving the productivity by 3.4 fold. Combining this approach together with the overexpression of a truncated form of 3-hydroxyl-3-methyl-glutaryl-CoA reductase (HMGR) and deletion of lipid phosphate phosphatase encoded by LPP1 led to a strain with a productivity of 0.18mg/gDCWh. The titer was further increased by deleting DPP1 encoding a second FPP consuming pyrophosphate phosphatase yielding a final productivity and titer, respectively, of 0.21mg/gDCWh and 92mg/l of α-santalene.
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden.
authors.forename: Gionata
authors.initials: G
authors.lastname: Scalcinati
authors.forename: Christoph
authors.initials: C
authors.lastname: Knuf
authors.forename: Siavash
authors.initials: S
authors.lastname: Partow
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.forename: Jérôme
authors.initials: J
authors.lastname: Maury
authors.forename: Michel
authors.initials: M
authors.lastname: Schalk
authors.forename: Laurent
authors.initials: L
authors.lastname: Daviet
authors.forename: Jens
authors.initials: J
authors.lastname: Nielsen
authors.forename: Verena
authors.initials: V
authors.lastname: Siewers
mesh_terms: D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000096:biosynthesis* / Q000235:genetics; D017353:Gene Deletion; D051246:Glucose Transport Proteins, Facilitative / Q000235:genetics; D006903:Hydroxymethylglutaryl CoA Reductases / Q000096:biosynthesis* / Q000235:genetics; D060847:Metabolic Engineering; D008798:Mevalonic Acid / Q000378:metabolism; D010711:Phosphatidate Phosphatase / Q000235:genetics; D010944:Plants / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis* / Q000235:genetics; D012717:Sesquiterpenes / Q000737:chemistry / Q000378:metabolism*
chemical_list: D051246:Glucose Transport Proteins, Facilitative; C090594:HXT1 protein, S cerevisiae; C084498:HXT2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D012717:Sesquiterpenes; D006903:Hydroxymethylglutaryl CoA Reductases; C496127:ERG9 protein, S cerevisiae; D013186:Farnesyl-Diphosphate Farnesyltransferase; C112948:lipid phosphate phosphatase; D010711:Phosphatidate Phosphatase; D008798:Mevalonic Acid