Isolation of Phaffia Rhodozyma Auxotrophic Mutants by Enrichment Methods

Abstract

To establish the optimal conditions for mutagenesis in the astaxanthin-producing yeast Phaffia rhodozyma when different mutagens are used, dose-response curves for UV radiation, ethyl methanosulfonate and N-methyl-N’-nitro-N-nitrosoguanidine were constructed. An enrichment scheme using the polyene antibiotic nystatin for the isolation of auxotrophic mutants was designed. This treatment resulted in auxotrophic isolates at a frequency of 1 × 10 -3. Uracil-requiring mutants were obtained by 5-fluoro-orotic acid selection at a frequency of 1.67 × 10 -7. © 1993, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation. All rights reserved.