Improved production of carotenes from synthetic medium by Blakeslea trispora in a bubble column reactor

The carotene production from a synthetic medium sterilized at initial pH 11.0 by Blakeslea trispora in a bubble column reactor was investigated. Under the above conditions the fungus formed compact aggregates (pellets). As a consequence, a mild oxidative stress in B. trispora was occurred indicated by the specific activities of superoxide dismutase (SOD) and catalase (CAT). The oxidative stress resulted in a significant increase in carotene production and a change in the biosynthesis of carotenes. The highest concentration of carotenes (85.0 mg/g dry biomass) was obtained after 8 days of fermentation. In this case, the proportion of β-carotene, γ-carotene, and lycopene was 52.42%, 45.43%, and 2.15%, respectively. Bubble column reactor has a potential for carotene production from synthetic medium sterilized at initial pH 11.0.

► The fungus B. trispora grown in a bubble column reactor formed pellets.
► This resulted in a mild oxidative stress in B. trispora.
► The oxidative stress increased significantly the carotene production.
► Bubble column reactor was a useful fermentation system for carotene production.