University of Stellenbosch. Faculty of AgriSciences. Institute for Wine Biotechnology


Project Number
IWBT 05-02

Project title
The improvement of the fermentation performance of yeast

Project leader
Bauer, F F

Institution
University of Stellenbosch. Faculty of AgriSciences. Institute for Wine Biotechnology

Team members
Arensburg, Y
Muller-Patterton, H E
Styger, G
Van Dyk, D
Berthels, N J
Franken, C J

Project description
Performance Program were achieved during the previous year. These include:
A questionnaire that assessed winery performances, including the occurrence of stuck and sluggish fermentations, was developed and sent to 320 wineries. Sixty-five completed questionnaires were received, corresponding to a return of close to 20%. These questionnaires have allowed to assess the occurrence of sluggish and stuck fermentations, and to establish correlations between such problem fermentations and other cellar operations.

The first stage of the project involved the optimisation of certain fermentation techniques. To this end a three-month training period was undertaken at the Department of Chemical and Bioprocess Engineering at the Pontificia Universidad Catolica de Chile. Upon return to Stellenbosch, triplicate large-scale fermentations were carried out on synthetic grape must, under controlled conditions. Samples were taken for metabolite analysis and RNA extraction, at six hourly intervals during the course of the fermentation. The RNA was used for subsequent analysis by using SAGE and microarrays.

Mss11p is a key factor in the regulation of nutrient-dependent cellular differentiation, including invasive growth, starch degradation and flocculation. The transcription factors Flo8p, Msn1p, Phd1p, Ste12 and Tec1p all require a functional MSS11 gene to fully induce MUC1 and STA2 expression and hence to establish invasion and starch degradation. Rme1p was shown to regulate MUC1 and STA2 independently of all the transcription factors tested, including Mss11p. This result places Rme1p in a novel regulatory pathway.

Our directed strain development programme aims at improving general hexose utilisation and fructose utilisation in particular. In order to understand why S. cerevisiae uses glucose preferentially before fructose and to develop yeast strains with similar affinity and consumption rates for both hexoses, several strategies were implemented. Mutants in the hexokinase encoding genes and in different hexose transporters were analysed. Also the overexpression of two plant fructokinase genes and the overexpression and deletion of the yeast xylulokinase gene (XKS1) were assessed. A fructose transporter was cloned and heterologously expressed in yeast. All overexpressing strategies, except the overexpression of plant fructokinases, proved successful.

Poster(s)
Van Dyk, D, J, Pretorius, I S and Bauer, F F. 2003. Rme 1p induces MUC1/FLO11 expression through an 11 bp Rme1p response element. Poster presented at the 21st International Conference on Yeast Genetics and Molecular Biology. 7-12 July 2003, Göteborg, Sweden.

Van Dyk, D J, Pretorius, I S and Bauer, F F. 2005. Mode of action for Mss11p: a central factor in the FLO transcription machinery. Poster presented at the 22nd International Conference of Yeast Genetics and Molecular Biology. August 7-12, 2005, Bratislava, Slovakia.

Presentation(s)
Berthels, N, Patterson, H E, Bauer, F F, Thevelein, J M and Pretorius, I S. 2001. Improvement of fructose consumption in wine by Saccharomyces cerevisiae. Paper presented at the 20th International Conference on Yeast Genetics and Molecular Biology. Prague, Czech Republic.

Berthels, N, Patterson, H E, Bauer, F F, Thevelein, J M and Pretorius, I S. 2001. Improvement of fructose consumption in wine by Saccharomyces cerevisiae. Paper presented at the 25th National Congress of the South African Society for Enology and Viticulture. 15-16 November, Somerset West, South Africa

Berthels, N, Patterson, H E, Bauer, F F, Thevelein, J M and Pretorius, I S. 2002. Improvement of fructose consumption in wine by Saccharomyces cerevisiae. Paper presented at the 22nd International Specialised Symposium on Yeasts. 25-28 March 2002. Pilanesberg, South Africa.

Styger, G, Van Dyk, D, Arensburg, J, Pretorius, I S and Bauer F F. 2002. Genome-wide transcription in yeast. Using SAGE and microarrays to analyse transcription factor networks and stress response. Presentation to the UCT-SANBI Bio-Informatics. Cape Town, South Africa.

Berthels, N J, Cordero Otero, R R, Bauer, F F, Thevelein, J M and Pretorius, I S. 2003. Factors that affect the consumption of fructose by Saccharomyces cerevisiae wine strains. Paper presented at the 21st International Conference on Yeast Genetics and Molecular Biology. 7-12 July, Göteborg, Sweden.

Van Dyk, D J, Pretorius, I S and Bauer, F F. 2003. Rme 1p induces MUC1/FLO11 expression through an 11 bp Rme1p response element. Paper presented at the 21st International Conference on Yeast Genetics and Molecular Biology. 7-12 July, Göteborg, Sweden.

Bester, M C, Franken, C J and Bauer, F F. 2003. Regulation of Ca2+-dependant flocculation by Saccharomyces cerevisiae transcriptional regulator Mss11p. Paper presented at the 21st International Conference on Yeast Genetics and Molecular Biology. 7-12 July, Göteborg, Sweden.

Berthels, N J, Cordero Otero, R, Bauer, F F, Thevelein, J M and Pretorius I S. 2003. Discrepancy in glucose and fructose utilisation during fermentation by Saccharomyces cerevisiae wine yeast. Paper presented at the 25th National Congress of the South African Society for Enology and Viticulture. 15-16 November, Somerset West, South Africa.

Bester, M C, Franken, C J, Van Dyk, D, Gagiano, M, Pretorius, I S and Bauer, F F. 2004. Regulation of Ca2+-dependant flocculation by Saccharomyces cerevisiae transcriptional regulator Mss11p. Paper presented at the 13th South African Society for Microbiology Conference. April 2004, Stellenbosch, South Africa.

Louw, C, La Grange, D, Pretorius, I S and Van Rensburg, P. 2004. Challenging traditional winemaking practices with yeast biotechnological innovations. Paper presented at the 13th South African Society for Microbiology Conference. April 2004, Stellenbosch, South Africa.

Berthels, N J, Cordero Otero, R, Bauer, F F, Thevelein, J M and Pretorius I S. 2004. Fructose utilisation by the alcoholic wine yeast Saccharomyces cerevisiae. Paper presented at the 18th Congress of the South African Genetics Society. 4-7 April, Stellenbosch, South Africa.

Van Dyk, D, Pretorius, I S and Bauer, F F. 2005. Mss11p is central to the regulation of FLO11 gene transcription and invasive growth in Saccharomyces cerevisiae. Paper presented at the 22nd International Conference of Yeast Genetics and Molecular Biology. 7-12 August 2005, Bratislava, Slovakia.

Du Toit, M. 2005. Problem fermentations: experiences of the season. Presentation at the South African Society for Enology and Viticulture and Anchor Biotechnology Winter Workshop, Cape Town, South Africa.

Van Dyk, D, Pretorius, I S and Bauer, F F. 2005. Mode of action for Mss11p: a central factor in the FLO11 transcription machinery. Paper presented at the 22nd International Conference of Yeast Genetics and Molecular Biology. 7-12 August, Bratislava, Slovakia.

Malherbe, S, Du Toit, M, Bauer, F F and Nieuwoudt, H H. 2005. A simple and effective strategy for the selection of calibration samples for FT-IR spectroscopy. Paper presented at the 3rd International Congress of the South African Society for Enology and Viticulture. 7-8 November, Cape Town, South Africa

Malherbe, S, Du Toit, M, Nieuwoudt, H H and Bauer, F F. 2005. Problem fermentations: an industrial case study investigating the discrimination possibilities of FT-IR spectroscopy. Paper presented at 3rd International Congress of the South African Society for Enology and Viticulture. 7-8 November, Cape Town, South Africa.

Malherbe, S, Du Toit, M, Nieuwoudt, H H and Stander, M A. 2005. Simultaneous quantification of the main organic acids, sugars, glycerol and ethanol in wine using HPLC. Paper presented at 3rd International Congress of the South African Society for Enology and Viticulture. 7-8 November, Cape Town, South Africa.

Malherbe, S, Du Toit, M, Bauer, F F and Nieuwoudt, H H. 2007. A simple and effective strategy for the selection of calibration samples for FT-IR spectroscopy. Paper presented at the In Vino Analytica Scientia Symposium. 22-25 July 2007, Melbourne, Australia.

Malherbe, S, Du Toit, M, Nieuwoudt, H H and Stander, M A. 2007. Simultaneous quantification of the main organic acids, sugars, glycerol and ethanol in wine using HPLC. Paper presented at the In Vino Analytica Scientia Symposium. 22-25 July 2007, Melbourne, Australia.

Malherbe, S, Du Toit, M, Nieuwoudt, H H and Bauer, F F. 2007. Problem fermentations: an industrial case study investigating the discrimination possibilities of FT-IR spectroscopy. Paper presented at the 13th Australian Wine Industry Technical Conference. 28 July – 2 August 2007, Adelaide, Australia.

Malherbe, S, Du Toit, M, Nieuwoudt, H H and Stander, M A. 2007. Simultaneous quantification of the main organic acids, sugars, glycerol and ethanol in wine using HPLC. Paper presented at the 13th Australian Wine Industry Technical Conference. 28 July – 2 August 2007, Adelaide, Australia.

Article
Bauer, F F, Pretorius, I S. 2000. Yeast stress response and fermentation efficiency: How to survive the making of a wine – a review, South African Journal of Enology and Viticulture, v. 21 Special issue (27-51)

Gagiano, M, Bester, M, Van Dyk, D, Franken, J, Bauer, F F, Pretorius, I S. 2003. Mss11p is a transcription factor regulating pseudohyphal differentiation, invasive growth and starch metabolism in Saccharomyces cerevisiae in response to nutrient availability, Molecular Microbiology, Mnth 47 v. 1 (119-134)

Van Dyk, D, Hansson, G R, Pretorius, I S, Bauer, F F. 2003. Cellular differentiation in response to nutrient availability: the repressor of meiosis, RME1p, positively regulates invasive growth in Saccharomyces cerevisiae, Genetics, Mnth Jan v. 165 (3) (p. 1045-1058)

Sheridan, C M, Bauer, F F, Burton, S, Lorenzen, L. 2005. A critical process analysis of wine production to improve cost, quality and environmental performance, Water Science and Technology, v. 51 (1) (p. 39-46)

Van Dyk, D, Pretorius, I S, Bauer, F F. 2005. Mss11p is a central element of the regulatory network that controls FLO11 expression and invasive growth in Saccharomyces cerevisiae, Genetics, Mnth Jan v. 169 (1) (p. 91-96)

Berthels, N J, Cordero Otero, R R, Bauer, F F, Thevelien, J M, Pretorius, I S. 2006. Discrepancy in glucose and fructose utilisation during fermentation by Saccharomyces cerevisiae in wine yeast strains, FEMS Yeast Research, v. 4 (7) (p. 683-689)

Malherbe, S, Bauer, F F, Du Toit, M. 2006. Industry wide investigation into the occurrence and causes of problem fermentations, WineLand, Mnth Jan (p. 89-91)

Malherbe, S, Bauer, F F, Du Toit, M. 2007. Understanding problem fermentations, South African Journal of Enology and Viticulture, v. 28 (2) (p. 169-186)
Article.pdf

Berthels, N J, Cordero Otero, R R, Bauer, F F, Pretorius, I S, Thevelien, J M. 2008. Correlation between glucose and fructose discrepancy and hexokinase kinetic properties in different Saccharomyces cerevisiae wine yeast strains, Applied Microbiology and Biotechnology, v. 77 (5) (p. 1083-1089)

Malherbe, S, Du Toit, M. 2008. Problem fermentations – facts, solutions and methods, www.newworldwinemaker.com.
www.newworldwinemaker.com

FinalReport.pdf

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