Yong-Cheol Park, Soo-Jung Kim, Jin-Ho Choi, Won-Heong Lee, Kyungmoon Park, Mokoto Kawamukai, Yeon-Woo Ryu and Jin-Ho Seo. Batch and fed-batch production of Coenzyme Q10 in recombinant Escherichia coli containing the decaprenyl diphosphate synthase gene from Gluconobacter suboxydans. Applied Microbiology and Biotechnology 67: 192-196 (2005) 

Coenzyme Q10 (CoQ10) is a quinine consisting of ten units of the isoprenoid side-chain. Because it limits the oxidative attack of free radicals to DNA and lipids, CoQ10 has been used as an antioxidant for foods, cosmetics and pharmaceuticals. Decaprenyl diphosphate synthase (DPS) is the key enzyme for synthesis of the decaprenyl tail in CoQ10 with isopentenyl diphosphate. The ddsA gene coding for DPS from Gluconobacter suboxydans was expressed under the control of an Escherichia coli constitutive promoter. Analysis of the cell extract in recombinant E. coli BL21/pACDdsA by high performance liquid chromatography and mass spectrometry showed that CoQ10 rather than endogenous CoQ8 was biologically synthesized as the major coenzyme Q. Expression of the ddsA gene with low copy number led to the accumulation of CoQ10 to 0.97 mg/L in batch fermentation. A high cell density (103 g/L) in fed-batch fermentation of E. coli BL21/pACDdsA increased the CoQ10 concentration to 25.5 mg/L and its productivity to 0.67 mg/L-h, which were 26.0 and 6.9 times higher than the corresponding values for batch fermentation.