Fig 1.
Biosynthetic pathway of β-carotene in recombinant S. cerevisiae.
The dashed lines indicate multiple step reactions. HMG1: HMG-CoA reductase, ERG9: squalene synthase. Carotenoids pathway: CrtE: GGPP synthase, BTS1: S. cerevisiae GGPP synthase, CrtYB: Lycopene cyclase, CrtI: Phytoene desaturase. IPP: isopentenyl pyrophosphate; DMAP: dimethylallyl pyrophosphate; GPP: geranyl pyrophosphate; FPP: farnesyl pyrophosphate; GGPP: geranylgeranyl pyrophosphate.
Fig 2.
Cell growth (A) and glucose consumption (B) of recombinant S. cerevisiae T73-63 and parent strain T73-4 and β-carotene concentration and production (C) of recombinant S. cerevisiae T73-63. Values represent the average of three independent cultures, and error bars correspond to the standard deviation (P< 0.05, Student’s t test).
Fig 3.
Time courses of intracellular amino acids concentration (μmol/g) of recombinant S. cerevisiae T73-63 (marked grey) and parent strain T73-4 (marked white).
Values represent the average of three independent cultures, and error bars correspond to the standard deviation (P< 0.05, Student’s t test).
Fig 4.
Time courses of relative concentration of metabolites in recombinant S. cerevisiae T73-63 (marked grey) and parent strain T73-4 (marked white).
Values represent the average of three independent cultures, and error bars correspond to the standard deviation (P< 0.05, Student’s t test).
Fig 5.
Cell growth of recombinant S. cerevisiae T73-63 in mixed carbon source cultures and YPD medium containing 2% and 5% glucose, respectively.
Values represent the average of three independent cultures, and error bars correspond to the standard deviation (P< 0.05, Student’s t test). Abbreviations: Glu: glucose, Gly: glycerol, Gala: galactose, AceNa: sodium acetate, CitrNa: sodium citrate.
Fig 6.
β-Carotene concentration (A) and production (B) of recombinant S. cerevisiae T73-63 in mixed carbon source cultures and YPD medium containing 2% and 5% glucose, respectively at 12, 16 and 20 h. Values represent the average of three independent cultures, and error bars correspond to the standard deviation (P< 0.05, Student’s t test). Abbreviations: Glu: glucose, Gly: glycerol, Gala: galactose, AceNa: sodium acetate.
Fig 7.
Cell growth of recombinant S. cerevisiae T73-63 with different acetate supplementation modes.
Values represent the average of three independent cultures, and error bars correspond to the standard deviation (P< 0.05, Student’s t test). Abbreviations: Glu: glucose, AceNa: sodium acetate.
Fig 8.
The β-carotene concentration (A) and production (B) of recombinant S. cerevisiae T73-63 with different acetate supplementation modes. Values represent the average of three independent cultures, and error bars correspond to the standard deviation (P< 0.05, Student’s t test). Abbreviations: Glu: glucose, AceNa: sodium acetate.
Fig 9.
Relative concentration of metabolites in recombinant S. cerevisiae T73-63 supplemented with 10 g/l acetate at 10 h (marked grey) and T73-63 (marked white) at 12 and 16 h.
Values represent the average of three independent cultures, and error bars correspond to the standard deviation (P< 0.05, Student’s t test).
Fig 10.
The conversion pathway of acetate into β-carotene in recombinant S. cerevisiae.
Acetate addition are shown in red, central metabolite (acetyl-CoA) are shown in rose. The dashed lines represent multiple step reactions, double arrows indicate the enhancement of metabolic flow. ACS1/ACS2: Acetyl-CoA synthetase, FPP: farnesyl pyrophosphate, MVA pathway: mevalonate pathway.