Mutagenesis of Rhodobacter sphaeroides using atmospheric and room temperature plasma treatment for efficient production of coenzyme Q10

Abstract

Coenzyme Q10 (CoQ10) plays an important role in the human respiratory chain and is widely used as medicine and dietary supplement. To improve the fermentation efficiency of CoQ10, a modified version of atmospheric and room temperature plasma (ARTP) treatment was used to mutate Rhodobacter sphaeroides. Meanwhile, Vitamin K3, a structural analog of CoQ10, was used as an inhibitor for mutant selection. In the first round of screening in 24-well plates, three mutants were obtained, with the production of CoQ10at 311mg/L, 307mg/L, and 309mg/L, which were increased from the parent's production at 265mg/L. Furthermore, a second round of mutation and screening was performed based on the mutant strain with the highest production in the first round, leading to the identification of a mutant AR01 with the production of CoQ10at ∼330mg/L. Finally, 590mg/L CoQ10 was obtained for AR01 after 100h fermentation, which was ∼25.5% higher than that of the original parent strain. It is the first report of ARTP treatment usage for the selection of CoQ10 producing bacteria and the results show that plasma jet, driven by helium-based ARTP, can be a feasible strategy for mutation feeding.