The Escherichia coli ß-Glucuronidase Gene as a Marker for Saccharomyces Yeast Strain Identification

Abstract

The ß-glucuronidase (GUS) gene has been adapted for expression in yeast by ligating the Saccharomyces cerevisiae alcohol dehydrogenase promoter and terminator sequences to the coding region of the Escherichia coli uidA gene. Introduction of this construct into a wine yeast strain by integration into the ILV2 gene of chromosome XIII resulted in expression of ß-glucuronidase. The construct was maintained stably in a growing yeast population and no adverse effects were detected on the fermentation properties of the transformed yeast strain. A simple assay procedure has been devised to detect GUS activity in yeast cells or colonies. This method provides a means for genetic marking, and consequently identification, of wine yeast strains of choice.