Yeast Mutants Containing Elevated Methionine

摘要

ABSTRACTMutants ofCandida tropicalisATCC1369,Candida tropicalisATCC9968andCandida utilisATCC9950were produced by treatments with ultraviolet light (UV), ethionine, or nitrous acid (NA). The UV and NA derived mutants grew on a methionine‐free medium and exhibited an increased growth response to added sulfate in a sulfate‐free medium. The mutant 1369/0 had an increase of54.6methionine as a percentage of protein above that of the parent strain. The increase of the mutant1369/0over the parent in relative nutritive value ( RNV) was4.35. Sonication of yeast cells increased the RNV and average of8above that of the intact c