Optimization of β‐Carotene Production by Rhodotorula glutinis Using High Hydrostatic Pressure and Response Surface Methodology

Abstract

Rhodotorula glutinis RG6 was treated by high hydrostatic pressure (HHP) of 300 MPa for 15 min for improving its ability of beta-carotene production. After the treatments of 5 repeated cycles, the mutant strain RG6p was obtained, beta-carotene production of which reached 10.01 mg/L, increased by 57.89% compared with 6.34 mg/L from parent strain RG6. To optimize the medium for beta-carotene fermentation by mutant RG6p, a response surface methodology (RSM) approach was used in conjunction with a factorial design and a central composite design, and the maximum yield of beta-carotene (13.43 mg/L), an increase of 34.17% compared to the control, was obtained at a pH 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 (NH(4))(2)SO(4) (5 g/L).

Improvement of Coenzyme Q10 Production: Mutagenesis Induced by High Hydrostatic Pressure Treatment and Optimization of Fermentation Conditions

“…The present study found that HHP treatment can have beneficial mutagenic effects on A. tumefaciens for CoQ10 production, which agrees with the finding of Wu et al [21] who found that the bacterial cellulose mutant M 438 was obtained after HHP treatment at 250 MPa for 15 min. Wang et al [19, 20] obtained the barotolerant mutant PR68 after five repeated cycles of HHP treatment at 300 MPa for 12 min. They found that the DNA segments of mutant PR68 were different from the original strain.…”

“…There were also reports that HHP treatment in laboratory could cause beneficial mutagenesis to E. coli [17, 18], R. glutinis [19, 20], and G. xylinus [21]. Compared with traditional physical and chemical mutagenesis methods, HHP treatment as a mutagen could offer some advantages such as easier handling, savings in time and money, and negligible effects to the environment [19, 20]. However, little is known related to the effectiveness of HHP treatment on improving the production of CoQ10 in microorganisms.…”

Biosynthetic Pathway of Carotenoids in Rhodotorula and Strategies for Enhanced Their Production

“…Bhosale et al [26] obtained a mutant 32 (2,048 μg/g) of a wild strain R. glutinis NCIM 3353 by UV radiation, which led to a yield increase of β-carotene in mutant 32 by 120-fold, as compared to that in the parent strain. Similarly, Wang et al [27] was able to increase the yield of β-carotene by 57.89% in mutant strain RG6p, by using five repeated cycles of high hydrostatic pressure (HHP) mutation of the parent isolate R. glutinis GR6. Significant carotenoid yield improvement in R. mucilaginosa RM-1 was also documented by mutagenesis manipulation using N+ implantation of 10 keV and 2.0 × 10 1 4 ion/cm 2 [28].…”

Carotenoids from Rhodotorula and Phaffia: yeasts of biotechnological importance

“…The mutant produced insigniWcant amount of torularhodin, which can be related to aVected oxydase activity. Later, Wang et al [105] after the treatments of Wve repeated cycles by high hydrostatic pressure of 300 MPa, the mutant R. glutinis RG6p was obtained, -carotene production of which reached 10.01 mg/l, increased by 57.89% compared with 6.34 mg/l from parent strain.…”

“…Mutagenic treatment with N-methyl-NЈ-nitro-N-nitrosoguanidine (NTG), UV light, antimycin, ethyl-methane sulfonate, -irradiation, high hydrostatic pressure have been used successfully to isolate various strains with enhanced carotenoid-producing activity [62,66,83,85,86,[100][101][102][103][104][105].…”