2009 Science News of the Year: Nutrition
That yeast smells good
Yeast has long been pressed into service for making beer and bread. Now the fungus has been tapped for a loftier flavor: vanillin, vanilla’s dominant compound (SN: 5/23/09, p. 9). Natural vanilla comes from the pods, or beans, of two orchid species, and the extract can be costly. So the majority of vanillin is synthesized in chemistry labs, a process that often requires expensive starter compounds. Danish scientists skirted these costs by genetically engineering two yeast species, strains of beer and baker’s yeast, to make vanillin from glucose, which is cheap and available. Genes spliced into the yeasts include one from a dung mold, two bacterial genes and a human gene. “This is absolutely beautiful work,” says John Rosazza, a medicinal and natural products chemist at the University of Iowa in Iowa City. There is a huge commercial market for vanillin, he notes.
