Dissolved-oxygen feedback control fermentation for enhancing β-carotene in engineered Yarrowia lipolytica

Abstract

The DO-stat fed-batch fermentation was carried out to explore the volumetric productivity of β-carotene in engineered Yarrowia lipolytica C11 strain. Using DO-stat fed-batch fermentation, we achieved 94 g/L biomass and 2.01 g/L β-carotene. Both biomass and β-carotene were about 1.28-fold higher than that in fed-batch fermentation. The ATP, NADP+/NADPH, and gene expression levels of tHMG, GGS1, carRA, and carB were promoted as compared to that in fed-batch fermentation. As for as the kinetic parameters in DO-stat fed-batch fermentation, μm′, Yx/s′, and Yp/s′ was 0.527, 0.353, and 0.158, respectively. The μm′ was elevated 4.66-fold than that in fed-batch fermentation. These data illustrate that more dissolved oxygen increased the biomass. The Yx/s′ and Yp/s′ were increased 1.15 and 22.57-fold, which suggest that the DO-stat fed-batch fermentation reduced the Crabtree effect and improved the utilization rate of glucose. Therefore, DO-stat fed-batch fermentation is a promising strategy in the industrialized production of β-carotene.