Improved β-carotene production of Rhodotorula glutinis in fermented radish brine by continuous cultivation

Fermentation kinetics of growth and β-carotene production by Rhodotorula glutinis DM28 in batch and continuous cultures using fermented radish brine, a waste generated from fermented vegetable industry, as a cultivation medium were investigated. The suitable brine concentration for β-carotene production by R. glutinis DM28 was 30 g l−1. Its growth and β-carotene production obtained by batch culture in shake flasks were 2.2 g l−1 and 87 μg l−1, respectively, while, in a bioreactor were 2.6 g l−1 and 186 μg l−1, respectively. Furthermore, its maximum growth rate and β-carotene productivity in continuous culture obtained at the dilution rate of 0.24 h−1 were 0.3 g l−1 h−1 and 19 μg l−1 h−1, respectively, which were significantly higher than those in the batch. Therefore, improved growth rate and β-carotene productivity of R. glutinis in fermented radish brine could be accomplished by continuous cultivation.