Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Ergosterol production from molasses by genetically modified Saccharomyces cerevisiae


Ergosterol is an economically important metabolite produced by fungi. Recombinant Saccharomyces cerevisiae YEH56(pHXA42) with increased capacity of ergosterol formation was constructed by combined overexpression of sterol C-24(28) reductase and sterol acyltransferase in the yeast strain YEH56. The production of ergosterol by this recombinant strain using cane molasses (CM) as an inexpensive carbon source was investigated. An ergosterol content of 52.6 mg/g was obtained with 6.1 g/l of biomass from CM medium containing 60 g/l of total sugar in 30 h in shake flask. The ergosterol yield was enhanced through the increasing cell biomass by supplementation of urea to a concentration of 6 g/l in molasses medium. Fermentation was performed in 5-l bioreactor using the optimized molasses medium. In batch fermentation, the effect of agitation velocity on ergosterol production was examined. The highest ergosterol yield was obtained at 400 rpm that increased 60.4 mg/l in comparison with the shake flask culture. In fed-batch fermentation, yeast cells were cultivated, firstly, in the starting medium containing molasses with 20 g/l of total sugar, 1.68 g/l of phosphate acid, and 6 g/l of urea (pH 5.4) for 5 h, then molasses containing 350 g/l of total sugar was fed exponentially into the bioreactor to keep the ethanol level in the broth below 0.5%. After 40 h of cultivation, the ergosterol yield reached 1,707 mg/l, which was 3.1-fold of that in the batch fermentation.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  1. Adams A, Gottschling DE, Kaiser CA, Stearns T (1997) Methods in yeast genetics. A cold spring harbor laboratory course manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York

  2. Alfafara GC, Miura K, Shimizu H, Shioya S, Suga K, Suzuki K (1993) Fuzzy control of ethanol concentration and its application to maximum glutathione production in yeast fed-batch culture. Biotechnol Bioeng 41:493–501

  3. Arnezeder C, Hampel WA (1990) Influence of growth rate on the accumulation of ergosterol in yeast cells. Biotechnol Lett 12:277–282

  4. Bradford MM (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein dye-binding. Anal Biochem 72:248–254

  5. Beshay U, Moreira A (2005) Production of alkaline protease with Teredinobacter turnirae in controlled fed-batch fermentation. Biotechnol Lett 27:1457–1460

  6. He XP, Huai WH, Tie CJ, Liu YF, Zhang BR (2000) Breeding of high ergosterol-producing yeast strains. J Ind Microbiol Biotechnol 25:39–44

  7. He XP, Zhang BR, Tan HR (2003) Overexpression of a sterol C-24(28) reductase increases ergosterol production in Saccharomyces cerevisiae. Biotechnol Lett 25:773–778

  8. He XP, Guo XN, Zhang BR, Tan HR (2004) Effect of overexpression of sterol-acyl transferase on ergosterol production in yeast strains. Acta Microbiol 44:67–71 (in Chinese)

  9. Hensing MCM, Ruowenhorst RJ, Heijnen JJ, van Dijken JP, Pronk JT (1995) Physiological and technological aspects of large-scale heterologous protein production with yeast. Antonie Van Leeuwenhoek 67:261–279

  10. Jensen-Pergakes K, Guo Z, Giattina M, Sturley SL, Bard M (2001) Transcriptional regulation of the two sterol esterification genes in the yeast Saccharomyces cerevisiae. J Bacteriol 183:4950–4957

  11. Lees ND, Bard M, Kirsch DR (1999) Biochemistry and molecular biology of sterol synthesis in Saccharomyces cerevisiae. Crit Rev Biochem Mol Biol 34:33–47

  12. Polakowski T, Bastl R, Stahl U, Lang C (1999) Enhanced sterol-acyl transferase activity promotes sterol accumulation in Saccharomyces cerevisiae. Appl Microbiol Biotechnol 53:30–35

  13. Qureshi N, Lolas A, Blaschek HP (2001) Soy molasses as fermentation substrate for production of butanol using Clostridium beijerinckii BA101. J Ind Microbiol Biotechnol 26:290–295

  14. Saha BC (2006) A low-cost medium for mannitol production by Lactobacillus intermedius NRRL B-3693. Appl Microbiol Biotechnol 72:676–680

  15. Sambrook J, Russell DW (2001) Molecular cloning, a laboratory manual, 3rd edn. Cold Spring Harbor Laboratory Press, New York

  16. Shang F, Wen S, Wang X, Tan T (2006) High-cell-density fermentation for ergosterol production by Saccharomyces cerevisiae. J Biosci Bioeng 101:38–41

  17. Solaiman DKY, Ashby RD, Nunez A, Foglia TA (2004) Production of sophorolipids by Candida bombicola grown on soy molasses as substrate. Biotechnol Lett 26:1241–1245

  18. Solaiman DKY, Ashby1 RD, Hotchkiss JAT, Foglia TA (2006) Biosynthesis of medium-chain-length poly(hydroxyalkanoates) from soy molasses. Biotechnol Lett 28:157–162

  19. Subbiah MT, Abplanalp W (2003) Ergosterol (major sterol of baker’s and brewer’s yeast extracts) inhibits the growth of human breast cancer cells in vitro and the potential role of its oxidation products. Int J Vitam Nutr Res 73:19–23

  20. Torija MJ, Beltran G, Novo M, Poblet M, Rozès N, Guillamòn JM, Mas A (2003) Effect of the nitrogen source on the fatty acid composition of Saccharomyces cerevisiae. Food Microbiol 20:255–258

  21. Yang H, Bard M, Bruner DA, Gleeson A, Deckelbaum RJ, Aljinovic G, Pohl TM, Rothstein R, Sturley SL (1996) Sterol esterification in yeast: a two-gene process. Science 272:1353–1356

  22. Zinser E, Paltauf F, Daum G (1993) Sterol composition of yeast organelle membranes and subcellular distribution of enzymes involved in sterol metabolism. J Bacteriol 175:2853–2858

Download references


The authors would like to acknowledge the financial support of the National Science Foundation of China, grant number 30470035.

Author information

Correspondence to Borun Zhang.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

He, X., Guo, X., Liu, N. et al. Ergosterol production from molasses by genetically modified Saccharomyces cerevisiae . Appl Microbiol Biotechnol 75, 55–60 (2007).

Download citation


  • Ergosterol
  • Combined overexpression
  • Sterol C-24(28) reductase
  • Sterol acyltransferase
  • Molasses
  • Fed-batch fermentation