Fermentation Production Of Coenzyme Q₁₀ By Rhodotorula Glutinis

In this paper, R. glutinis was chosen as the producer of CoQ10, and the optimization of fermentation process and metabolic regulation were studied.First, a series of statistical methods were used to optimize the culture conditions. Based on the single factor experiment, a screening experiment was conducted using orthogonal design to find the signiffcant factors affecting CoQ10 biosynthesis. Then, these factors and their interaction were studied by response surface methodology (RSM). A maximum biomass of R. glutinis 18.648g/L was achieved and the yield of CoQ10 was 16.405mg/L in the validation experiments under the optimal culture conditions obtained by RSM in shake flasks.Then, the fermentation kinetics of CoQ10 production with R. glutinis were studied. The mathematical kinetic models were obtained. And the simulated results were agreed well with the experimental data and could provide a reasonable description for biomass, products and substrate variation during the fermentation process. After that, the pH-control pulse fed-batch fermentation was taken into consideration, and the maximum biomass of R. glutinis and yield of CoQ10 reached 28.887g/L and 31.553mg/L, respectively. Finally, the effects of four chemical elicitors VB1, VH3, abscisic acid (ABA) and trisporoid acid (TA) on the biosynthesis of coenzyme Q10 were examined. Among them, the stimulation of ABA and TA was remarkabe. The results showed that when ABA and TA were added at the final concentration of 6 mg/L and 3mg/L, the yield of CoQ10 was 61.6% and 81.868% higher than that of the control, respectively. TA and ABA could stimulate very remarkably CoQ10 and ergosterol yields while lower the yield of B-carotenoid, and the effect of TA was higher than ABA. Adding 6mg/L ABA at 36h and combined with 3mg/L ketoconazole at 60h into medium made the yield of CoQ10 andβ-carotenoid 47.63% and 201.63% higher than that of the control, however, the yield of ergosterol 21.42% was lower than that of the control.Different organism inducing factors were researched to promote the yield of CoQ10 in this work. The results showed that when the crude extracts and the refined extracts of Laminaria Japonica were added at the concentration of 300ml/L and 4ml/L, the yield of CoQ10 was 4.54% and 11.59% higher than that of the control, respectively. The B. trispora elicitor had no effect on CoQ10 biosynthesis. The P. rhodozyma and S.cerevisiae elicitor concentration of 40mg/L and 10mg/L promoted the yield of CoQ10 21.66% and 7.33% higher than the control.