Enhancement of antroquinonol production during batch fermentation using pH control coupled with an oxygen vector

Background: Antroquinonol, a ubiquinone derivative that shows anticancer and anti-inflammatory activities, is produced during solid-state fermentation of Antrodia camphorata; however, it cannot be biosynthesized via conventional submerged fermentation.

Results: A method for enhancing the biosynthesis of antroquinonol by controlling pH and adding an oxygen vector in a 7 L bioreactor was studied. In shake-flask experiments, a maximum antroquinonol production of 31.39 ± 0.78 mg L^-1 was obtained by fermentation with adding 0.2 g L^-1 coenzyme Q₀ (CoQ₀ ), at the 96th hour. Following kinetic analysis of the fermentation process, pH control strategies were investigated. A maximum antroquinonol production of 86.47 ± 3.65 mg L^-1 was achieved when the pH was maintained at 5.0, which exhibited an increase of 348.03% higher than the batch without pH regulation (19.30 ± 0.88 mg L^-1 ). The conversion rate of CoQ₀ improved from 1.51% to 20.20%. Further research revealed that the addition of n-tetradecane could increase the production of antroquinonol to 115.62 ± 4.87 mg L^-1 by increasing the dissolved oxygen in the fermentation broth.

Conclusion: The results demonstrated that pH played an important role in antroquinonol synthesis in the presence of the effective precursor CoQ₀ . It was a very effective strategy to increase the yield of antroquinonol by controlling pH and adding oxygen vector. © 2018 Society of Chemical Industry.