After reading the post and some of the responses dealing with this question,
I wonder if it is possible that what is growing as reddish colonies on
the raffinose, etc. plates is a contaminant. Torula grows as a tangerine-
raspberry sherbet color and is quite happy on most kinds of Saccharomyces
media. If you have Torula, it will be quite vigorous and be essentially
prototrophic for growth on standard yeast dropout media.
bethmont at ksu.ksu.edu