Effect of limited oxygen supply on coenzyme Q(10) production and its relation to limited electron transfer and oxidative stress in Rhizobium radiobacter T6102.

Coenzyme Q(10) (CoQ(10)) productions from Rhizobium radiobacter T6102 were monitored under various oxygen supply conditions by controlling the agitation speeds, aeration rates, and dissolved oxygen levels. As the results, the CoQ(10) production was enhanced by limited oxygen supply. To investigate whether the CoQ(10) production is associated with its physiological functions of electron carrier and antioxidant, the effects of sodium azide and hydrogen peroxide on the CoQ(10) production were studied, showing that the CoQ(10) contents were slightly enhanced with increasing sodium azide (up to 0.4 mM) and hydrogen peroxide (up to 10 microM) concentrations. These results suggest the plausible mechanism where the limited electron transfer stimulating the environments of limited oxygen supply and oxidative stress could accumulate the CoQ(10), providing the relationship between the CoQ(10) physiological functions and its regulation system.