Department of Molecular and Cellular Biology Faculty . Dr. George van der Merwe

Email: gvanderm@uoguelph.ca

Office: SCIE 2243
Ext: 54298
Lab: SCIE 2201
Ext: 56653

Profile

My interest in yeast molecular and cellular biology started during my undergraduate years at the University of Stellenbosch in South Africa. I graduated with a B.Sc (Microbiology) and enrolled in graduate studies with the focus on understanding the regulation of nitrogen metabolism in Saccharomyces cerevisiae, the commonly used brewer's and wine yeast. These studies allowed to me complete parts of my Ph.D. at the University of Tennessee (Memphis), Brock University (CCOVI), and the University of British Columbia (WRC). As a Research Associate at the University of British Columbia I developed an interest in the adaptation of yeast to fermentation-related stresses. I joined the University of Guelph in 2002. My research focuses on understanding the molecular responses of yeast to environmental conditions. We use standard microbiology, molecular biology, cellular biology, and genetic techniques as well as advance tools such as genomics, proteomics and metabolomics to unravel the yeast's adaptation to environmental changes. Research performed in my laboratory is funded by the Canadian Foundation of Innovation (CFI), Ministry of Education, Development and Training (MEDT), Natural Sciences and Engineering Research Council of Canada (NSERC), Genome Canada and the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).

Education

B.Sc: University of Stellenbosch
Ph.D.: University of Stellenbosch
Research Associate: University of British Columbia

Research

Wine yeasts are confronted with an array of challenging conditions during vinification. Limiting nutrients, osmotic stress-inducing concentrations of sugars, antimicrobial agents such as killer toxins and fungicides, and increasing concentrations of ethanol produced during the fermentation are some of the stresses wine yeasts have to overcome. The molecular adaptations to these stresses include alterations in the transcriptome and proteome of the yeast. Such changes inadvertently affect the metabolome of the yeast. My laboratory focuses on understanding the molecular mechanisms that: (1) enable the adaptation of yeast to fermentation-related stresses, and (2) link molecular adaptation and metabolite production. Knowledge generated from this research would enable us to devise strategies to improve the stress tolerance, vitality, and efficiency of yeast during its performance of alcoholic fermentations.

Selected Publications

Snowdon, C., and van der Merwe, G. 2012. Regulation of Hxt3 and Hxt7 turnover converges on the Vid30 complex and requires inactivation of the Ras/cAMP/PKA pathway in Saccharomyces cerevisiae. PLoS One. 2012;7(12):e50458. doi: 10.1371/journal.pone.0050458. Epub 2012 Dec 5.

Christopher Snowdon, Ryan Schierholtz, Peter Poliszczuk, Stephanie Hughes, and George van der Merwe. 2009. ETP1 HL010c is a novel gene needed for the adaptation of Saccharomyces cerevisiae to ethanol. FEMS Yeast Res. 9:372-380.

Chris Hlynialuk, Ryan Schierholtz, Amanda Vernooy, and George van der Merwe 2008. Nsf1p/Ypl230wp participates in transcriptional activation during non-fermentative growth and in response to salt stress in Saccharomyces cerevisiae. Microbiology 154:2482-2491.

Chris Snowdon, Chris Hlynialuk, and George van der Merwe. 2008. Components of the Vid30c are needed for the rapamycin-induced degradation of the high-affinity hexose transporter Hxt7 in Saccharomyces cerevisiae. FEMS Yeast Res. 8:204-216.

Virginia D Marks, Shannan J Ho Sui, Daniel Erasmus, George K van der Merwe, Jochen Brumm, Wyeth W Wasserman, Jenny Bryan, and Hennie J J van Vuuren. 2008. Dynamics of the Yeast Transcriptome During Wine Fermentation Reveals the Fermentation Stress Response. FEMS Yeast Res.8:35-52.

Joana Coulon, John I Husnik, Debra L Inglis, George K van der Merwe, Aline Lonvaud, Daniel J Erasmus and Hennie J J van Vuuren. 2006. Metabolic engineering of Saccharomyces cerevisiae to minimize the production of ethyl carbamate in wine. Am. J. Enol. Vitic. 57(2):113-124.

Subden, R.E., Husnik, J.I., van Twest, R., van der Merwe, G.K., and van Vuuren, H.J.J. 2003. Autochthonous microbial population in a Niagara Peninsula icewine must. Food. Res. Int. 36:747-751.

Erasmus, D.J., van der Merwe, G.K., and van Vuuren, H.J.J. 2003. Genome-wide expression analyses: Metabolic adaptation of Saccharomyces cerevisiae to high sugar stress. FEMS Yeast Res. 3:375-399.

Marks, V.D., van der Merwe, G.K., and van Vuuren, H.J.J. 2003. Transcriptional profiling of wine yeast in fermenting grape juice: Regulatory effect of di-ammonium phosphate. FEMS Yeast Res. 3:269-287.

Dhanawansa, R., Faridmoayer, A., Li, P., van der Merwe, G.K., and Scaman, C. 2002. Overexpression, purification, and partial characterization of Saccharomyces cerevisiae processing alpha glucosidase I. Glycobiology 12:229-234.

van der Merwe, G.K., van Vuuren, H.J.J., and Cooper, T.G. 2001. Ammonia regulates VID30 expression and Vid30p function shifts nitrogen metabolism towards glutamate formation especially when Saccharomyces cerevisiae is grown in low concentrations of ammonia. J. Biol. Chem. 276:28659-28666.

van der Merwe, G.K., van Vuuren, H.J.J., and Cooper, T.G. 2001. Cis-acting sites contributing to expression of divergently transcribed DAL1 and DAL4 genes in Saccharomyces cerevisiae: a word of caution when correlating cis-acting sequences with genome-wide expression analyses. Curr. Genet. 39:156-165.

Graduate Students

Angus Ross (M.Sc.)
Recently Graduated: Chris Snowdon (Ph.D.), Kyrylo Bessonov (M.Sc.) and Ashley Hillier (M.Sc.)

Teaching

MCB*2050, MICR*3090, (MCB*4500/4510/4600 - W13) and MCB*6100/6200.
I participate in courses that provide senior undergraduate students with the opportunity to do research projects. For more details about these opportunities, please contact me directly.

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