Bob Sclafani

Dr. Robert A. Sclafani received his BA and PhD in Genetics from Columbia University in New York City. He did postdoctoral research in yeast genetics at the University of Washington in Seattle from 1981-1985. He has been brewing since 1982 after he took a course in home brewing from a fellow researcher in Seattle. He has consulted for several microbreweries and brewpubs including Wynkoop, Breckenridge, Tabernash and Columbine. He has been a Professor at the University of Colorado Health Sciences Center since 1985. His laboratory studies yeast cell growth and division and uses yeast as a model system to study cancer biology. His favorite beer is IPA.

Bob also has a day job. The main area of focus of his laboratory is the regulation of the G1 to S phase transition of the cell cycle in yeast and human cells. In G1, cells are sort of sitting around, growing quietly; in S, they are synthesizing DNA and getting ready to divide. Elucidation of the mechanisms of cell cycle control and cell commitment to DNA replication is important for determining the etiology of a number of diseases, especially cancer, in which the regulation is altered. Yeast (Saccharomyces cerevisiae), as an eukaryotic (that is, it has a nucleus like we do, unlike bacteria) microorganism is an excellent model system to study the cell cycle because facile molecular genetic techniques can be used in combination with classical biochemical and genetic methods. Saccharomyces means sugar-eating yeast; cerevisiae is from the Latin cerevisia, beer. They also use human cells in culture as a way to study the defects that are present in the cell cycle of cancer cells.

About the topic

At the Café, Bob pointed out that Brewer's yeast has lost almost all its "introns," the spacer regions between actual coding parts of genes which all eukaryotes (yeast, people) have. He thought that was probably due to their continuous culture and domestication by humans. When asked whether brewers use genetically-modified yeast for making beer, he said "I think everything we eat has been GM for centuries."

If you want more information about the biochemistry of respiration and fermentation see:

Stryer, L. Biochemistry, fifth edition, p373-526, W.H. Freeman and Co., New York, 2002.

The following are some references for those who are interested in finding out more detail about the yeast and brewing:

Sclafani, R.A. For the Beginner: Yeast at Work. Zymurgy 20: 45-47 (1997).

Fix, G. Principles of Brewing Science, p151-207, Brewers Publications, Boulder, CO, 1989.

Miller, D. Dave Miller’s Homebrewing Guide, p168-179, Story Communications, Inc., Pownal, VT, 1995.

You can keep up with yeast research and check out the Brewer's yeast genome database on line.

And don't forget, for further research, the Great Americal Beer Festival! →


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