PREPARATION OF A COPPER-DEFICIENT MEDIUM FOR YEAST GROWTH.

Giorgio, Anthony J. (University of Utah, Salt Lake City), G. E. Cartwright, and M. M. Wintrobe. Preparation of a copper-deficient medium for yeast growth. J. Bacteriol. 86:1037-1040. 1963.-A simple, rapid, and effective means was described for removing trace amounts of copper without removal of other growth nutrients from synthetic media. The complete synthetic medium minus added copper was batch-extracted with zinc dibenzyldithiocarbamate in carbon tetrachloride. The concentration of copper in extracted media was 0.3 to 1.7 mug per liter of media as compared with 8 mug per liter before extraction. Yeast growth in extracted media to which copper was added was comparable with growth in unextracted media. Yeast growth in copper-deficient media was significantly impaired. The growth requirement of two different strains of Saccharomyces cerevisiae was of the order of 10 mug of copper per liter of medium.