| 초록 |
A metabolically-engineered Deinococcus radiodurans R1 strain capable of producing phytoene, a colorless C40 carotenoid and a promising antioxidant, has been developed. First, the crtI gene encoding phytoene desaturase was deleted to block the conversion of phytoene to other carotenoids such as lycopene and γ-carotene. This engineered strain produced 0.413 ± 0.023 mg/l of phytoene from 10 g/l of fructose. Further enhanced production of phytoene up to 4.46 ± 0.19 mg/l was achieved by overexpressing the crtB gene encoding phytoene synthase and the dxs genes encoding 1-deoxy-D-xylulose-5-phosphate synthase gene, and by deleting the crtD gene. High cell-density culture of our final engineered strain allowed production of 10.3 ± 0.85 mg/l of phytoene with the yield and productivity of 1.04 ± 0.05 mg/g and 0.143 ± 0.012 mg/l/h, respectively. Furthermore, the antioxidant potential of phytoene produced by the final engineered strain was confirmed by in vitro DPPH radical-scavenging assay. |
