Enhancement Of Coenzyme Q₁₀ Production By Sphingomonas Sp. ZUTE03 With Mutants And Transformation-extraction Coupled Process

Coenzyme Q₁₀ (CoQ₁₀),a prenylated benzoquinone lipid,is also named ubiquinone. CoQ₁₀ is an important transferring- hydrogen carrier in biological respiratory chain and an antioxidant produced naturally. To today,it has been widely used in the treatment of cardio-cerebrovascular disease,hypertension,nervous system and skin diseases.It is used in the preparation of cosmetic products and health products as well.In this paper, we studied the ultraviolet induced mutation strain for producing CoQ₁₀, the effect of the supplementation of para-hydroxylbenzoate and solanesol on the biotransformation of CoQ₁₀.The Sphingomonas sp. ZUTE03 was treated with ultraviolet light (UV). Two screening models, Adriamycin (an analogu of Coenzyme Q₁₀)-resistent screening model and aromatic amino acids auxotroph screening model, were designed to obtain adriamycin-resistent mutant strains and aromatic amino acid auxotroph mutant strains with high production of CoQ₁₀, according to the biosynthetic pathway of coenzyme Q₁₀.The strains obtained were incubated in flask, and their productions of CoQ₁₀ were determined by high performance liquid chromatography. As a result, no adriamycin-resistent mutant strains were obtained. While three aromatic amino acid auxotrophic mutant strains, named E03-05, E03-16 and E03-36, were obtained. And the CoQ₁₀ yield of the strains E03-05, E03-16 and E03-36 were 0.383 mg/g-drycell, 0.343 mg/g-drycell, and 0.442 mg/g-drycell respectively, which reduced by 15.6%, 24.4%, and 7.7% in comparison to the CoQ₁₀ yield of initial strain (0.454 mg/g-drycell). In conclusion, no mutant strains of Sphingomonas sp. ZUTE03 with high CoQ₁₀ production were obtained.A transformation-extraction coupled process was evaluated for CoQ₁₀ production by free cells of Sphingomonas sp. ZUTEO3. The conditions were obtained as the follows: solanesol (750 mg/L) and para-hydroxylbenzoate (164.4 mg/L) in a transformation system containing 0.1 M phosphate buffer solution (10mL) as the aqueous phase, hexane (40 mL) as the organic phase respectively and 2% soybean oil as the cell membrane permeability. It was found that the CoQ₁₀ yield could reach the maximal value of 60.8 mg/L after 8 h.CoQ₁₀ could be produced by gel-entrapped cells with the transformation-extraction coupled process. It was also achieved to produce CoQ₁₀ by a repeated-batch culture of calcium alginate gel entrapped cells. The conditions were obtained as the follows: solanesol (500 mg/L) and para-hydroxylbenzoate (25 mg/L) in a transformation system containing 0.1 M Acetic acid buffer (25 mL) as the aqueous phase, hexane (25 mL) as the organic phase and 2% soybean oil as the cell membrane permeability respectively. It was found that the CoQ10 yield could reach the maximal value of 60.8 mg/L after 8 h. Even after 15 repeats, the yield of CoQ10 kept at a high level of more than 40 mg/L.