The Fermentation Conditions of beta-Carotene by the Red Yeast Mutant RG-6p

To optimize the beta-carotene fermentation medium of the mutant RG-6p (derived from Rhodotorula glutinis RG-6 with high hydrostatic pressure treatment), a response surface methodology (RSM) approach was used in conjunction with a factorial design and a central composite design. The maximum yield of beta-carotene (13.4 mg/L) was obtained at a pH of 6.7 with an optimum medium (40 mL/250 mL) of yeast extract (4.23 g/L), glucose (12.11 g/L), inoculum (30 mL/L), tomato extract (2.5 mL/L), peanut oil (0.5 mL/L), and (NH₄)₂SO₄ (5 g/L). Validity of the RSM approach was also confirmed by experiments.