title: High-cell-density cultivation for co-production of ergosterol and reduced glutathione by Saccharomyces cerevisiae.
abstract: Two different high-cell-density cultivation processes based on the mutant Saccharomyces cerevisiae GE-2 for simultaneous production of glutathione and ergosterol were investigated. Compared with keeping the ethanol volumetric concentration at a constant low level, feedback control of glucose feeding rate (F) by keeping the descending rate of ethanol volumetric concentration (DeltaE/Deltat) between -0.1% and 0.15% per hour was much more efficient to achieve a high glutathione and ergosterol productivity. This bioprocess overcomes some disadvantages of traditional S. cerevisiae-based cultivation process, especially shortening cultivation period and making the cultivation process steady-going. A classical on or off controller was used to manipulate F to maintain DeltaE/Deltat at its set point. The dry cell weight, glutathione yield and ergosterol yield reached 110.0 +/- 2.6 g/l, 2,280 +/- 76 mg/l, and 1,510 +/- 28 mg/l in 32 h, respectively.
authors: College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People's Republic of China.
authors: Fei
authors: F
authors: Shang
authors: Zheng
authors: Z
authors: Wang
authors: Tianwei
authors: T
authors: Tan
mesh_terms: D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D018929:Cell Culture Techniques / Q000379:methods*; D004875:Ergosterol / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D007218:Industrial Microbiology; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000431:Ethanol; D005978:Glutathione; D005947:Glucose; D004875:Ergosterol