Abstract:
Coenzyme Q
10 is an important hydrogen transmitter in respiratory chain, which plays an important role in the human body. It has been widely used for the treatment of cardiovascular and cerebrovascular diseases, and has been applied in cosmetics, health care products and other aspects. With the development of research, the market demand and industrial output of coenzyme Q
10 are constantly expanding. Microbial fermentation is the most promising method for the production of coenzyme Q
10 . This study used atmospheric and room temperature plasma (ARTP) towards
Rhodobacter sphaeroides to obtain mutants. Meanwhile, an oxygen-limited model was established to screen the strains which could suffer the low oxygen concentration. The bacterial suspension was treated by ARTP for 25 s, then cultured on the plate with 0.4 g/L sodium sulfite. The strains were fermented in 2.0 mL volume for 48 h. In the primary screening 24-well plates, 6 mutants were obtained. Furthermore, these mutants were cultured in shake flask to verify genetic stability. A mutant
R. sphaeroides F5D13 presented good stability and production of Coenzyme Q
10. The titer of
R. sphaeroides F5D13 was improved from 86.2 mg/L to 111.8 mg/L compared to the original strain. Finally, the yield of Coenzyme Q
10 reached 770.06 mg/L in 5 L fermentation after 100 h, which was increased by 18.0%. According to the fermentation parameters, the mutant
R. sphaeroides F5D13 showed the advantage of biomass in the cell growth phase and strong oxygen demand in product synthesis phase, which leaded to the higher oxygen uptake rate and yield than the original parent strain.