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The role of oxygen in yeast metabolism during high cell density brewery fermentations.
Appl Microbiol Biotechnol. 2009 Apr; 82(6):1143-56.AM

Abstract

The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e., higher inoculum size). However, the decreased yeast net growth observed in these high cell density fermentations can have a negative impact on the physiological stability throughout subsequent yeast generations. The use of different oxygen conditions (wort aeration, wort oxygenation, yeast preoxygenation) was investigated to improve the growth yield during high cell density fermentations and yeast metabolic and physiological parameters were assessed systematically. Together with a higher extent of growth (dependent on the applied oxygen conditions), the fermentation power and the formation of unsaturated fatty acids were also affected. Wort oxygenation had a significant decreasing effect on the formation of esters, which was caused by a decreased expression of the alcohol acetyl transferase gene ATF1, compared with the other conditions. Lower glycogen and trehalose levels at the end of fermentation were observed in case of the high cell density fermentations with oxygenated wort and the reference fermentation. The expression levels of BAP2 (encoding the branched chain amino acid permease), ERG1 (encoding squalene epoxidase), and the stress responsive gene HSP12 were predominantly influenced by the high cell concentrations, while OLE1 (encoding the fatty acid desaturase) and the oxidative stress responsive genes SOD1 and CTT1 were mainly affected by the oxygen availability per cell. These results demonstrate that optimisation of high cell density fermentations could be achieved by improving the oxygen conditions, without drastically affecting the physiological condition of the yeast and beer quality.

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Authors+Show Affiliations

Verbelen PJ
Centre for Malting and Brewing Science, Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, Box 2463, 3001 Heverlee, Belgium. Pieter.Verbelen@biw.kuleuven.be
Saerens SM
No affiliation info available
Van Mulders SE
No affiliation info available
Delvaux F
No affiliation info available
Delvaux FR
No affiliation info available

MeSH

BeerCulture MediaEstersFatty Acids, UnsaturatedFermentationGlycogenOxygenProteinsSaccharomycesSaccharomyces cerevisiae ProteinsTrehalose

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19263049

Citation

Verbelen, P J., et al. "The Role of Oxygen in Yeast Metabolism During High Cell Density Brewery Fermentations." Applied Microbiology and Biotechnology, vol. 82, no. 6, 2009, pp. 1143-56.
Verbelen PJ, Saerens SM, Van Mulders SE, et al. The role of oxygen in yeast metabolism during high cell density brewery fermentations. Appl Microbiol Biotechnol. 2009;82(6):1143-56.
Verbelen, P. J., Saerens, S. M., Van Mulders, S. E., Delvaux, F., & Delvaux, F. R. (2009). The role of oxygen in yeast metabolism during high cell density brewery fermentations. Applied Microbiology and Biotechnology, 82(6), 1143-56. https://doi.org/10.1007/s00253-009-1909-8
Verbelen PJ, et al. The Role of Oxygen in Yeast Metabolism During High Cell Density Brewery Fermentations. Appl Microbiol Biotechnol. 2009;82(6):1143-56. PubMed PMID: 19263049.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The role of oxygen in yeast metabolism during high cell density brewery fermentations. AU - Verbelen,P J, AU - Saerens,S M G, AU - Van Mulders,S E, AU - Delvaux,F, AU - Delvaux,F R, Y1 - 2009/03/05/ PY - 2008/12/11/received PY - 2009/02/03/accepted PY - 2009/02/03/revised PY - 2009/3/6/entrez PY - 2009/3/6/pubmed PY - 2009/5/5/medline SP - 1143 EP - 56 JF - Applied microbiology and biotechnology JO - Appl Microbiol Biotechnol VL - 82 IS - 6 N2 - The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e., higher inoculum size). However, the decreased yeast net growth observed in these high cell density fermentations can have a negative impact on the physiological stability throughout subsequent yeast generations. The use of different oxygen conditions (wort aeration, wort oxygenation, yeast preoxygenation) was investigated to improve the growth yield during high cell density fermentations and yeast metabolic and physiological parameters were assessed systematically. Together with a higher extent of growth (dependent on the applied oxygen conditions), the fermentation power and the formation of unsaturated fatty acids were also affected. Wort oxygenation had a significant decreasing effect on the formation of esters, which was caused by a decreased expression of the alcohol acetyl transferase gene ATF1, compared with the other conditions. Lower glycogen and trehalose levels at the end of fermentation were observed in case of the high cell density fermentations with oxygenated wort and the reference fermentation. The expression levels of BAP2 (encoding the branched chain amino acid permease), ERG1 (encoding squalene epoxidase), and the stress responsive gene HSP12 were predominantly influenced by the high cell concentrations, while OLE1 (encoding the fatty acid desaturase) and the oxidative stress responsive genes SOD1 and CTT1 were mainly affected by the oxygen availability per cell. These results demonstrate that optimisation of high cell density fermentations could be achieved by improving the oxygen conditions, without drastically affecting the physiological condition of the yeast and beer quality. SN - 1432-0614 UR - https://www.unboundmedicine.com/medline/citation/19263049/The_role_of_oxygen_in_yeast_metabolism_during_high_cell_density_brewery_fermentations_ L2 - https://dx.doi.org/10.1007/s00253-009-1909-8 DB - PRIME DP - Unbound Medicine ER -