Oxidative stress response of Blakeslea trispora induced by H2O2 during β-carotene biosynthesis

The cellular response of Blakeslea trispora to oxidative stress induced by H2O2 in shake flask culture was investigated in this study. A mild oxidative stress was created by adding 40 mu m of H2O2 into the medium after 3 days of the fermentation. The production of beta-carotene increased nearly 38 % after a 6-day culture. Under the oxidative stress induced by H2O2, the expressions of hmgr, ipi, carG, carRA, and carB involving the beta-carotene biosynthetic pathway all increased in 3 h. The aerobic metabolism of glucose remarkably accelerated within 24 h. In addition, the specific activities of superoxide dismutase and catalase were significantly increased. These changes of B. trispora were responses for reducing cell injury, and the reasons for increasing beta-carotene production caused by H2O2.