Editor: Guenther Daum
Oxygen is required to restore flor strain viability and lipid biosynthesis under fermentative conditions
Article first published online: 7 JAN 2009
© 2009 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Yeast Research
Volume 9, Issue 2, pages 217–225, March 2009
How to Cite
Zara, G., Angelozzi, D., Belviso, S., Bardi, L., Goffrini, P., Lodi, T., Budroni, M. and Mannazzu, I. (2009), Oxygen is required to restore flor strain viability and lipid biosynthesis under fermentative conditions. FEMS Yeast Research, 9: 217–225. doi: 10.1111/j.1567-1364.2008.00472.x
- Issue published online: 2 FEB 2009
- Article first published online: 7 JAN 2009
- Received 12 August 2008; revised 7 November 2008; accepted 10 November 2008.First published online 7 January 2009.
- Saccharomyces cerevisiae;
- flor yeast;
- lipid biosynthesis;
- real-time PCR
To further elucidate the biosynthesis of lipids in flor strains under fermentative conditions, the transcription levels of the lipid biosynthetic genes ACS1, ACS2, ACC1, OLE1, ERG1, ERG11, ARE1 and ARE2, as well as the lipid composition and cell viability of a flor strain were compared with that of a non-flor strain during hypoxic and aerobic fermentations in the absence of lipid nutrients. While no significant differences in transcription levels or lipid compositions were observed between the two strains when oxygen was not limiting, significant differences were seen during hypoxic fermentation. In this last condition, the flor strain, in spite of higher levels of transcription of hypoxic genes, lost the abilities to desaturate fatty acids and complete ergosterol biosynthesis, and showed a dramatic loss of viability. In contrast, the non-flor strain, which showed lower transcription levels, was able to reach a balanced lipid composition and maintained a higher cell viability. One possible explanation is that the flor strain requires a higher amount of oxygen than the non-flor strain in order to carry out the oxygen-dependent steps of lipid biosynthesis under fermentative conditions.