The Differential Effects of Nystatin on Growth of Auxotrophic and Prototrophic Strains of Aspergillus nidulans

摘要

SUMMARY: Nystatin affects the transfer of nutrients into fungal cells. Auxotrophs of Aspergillus nidulans vary in their susceptibility to nystatin, hence it is possible that they could be used to diagnose the effects of this antibiotic on cellular transport mechanisms for the uptake of different metabolites. Nystatin treatment can select auxotrophs from a largely prototrophic population in A. nidulans because newly germinated conidia are more sensitive to nystatin than ungerminated conidia. As the mycelium of germinated conidia ages it becomes less sensitive, so that critical conditions for maximum selection are a suitable period on minimal medium agar, sufficient only for germination of prototrophs, followed by the addition of nystatin in complete medium agar at a level which preferentially kills germinated conidia, thus allowing enrichment for ungerminated auxotrophic conidia. After treatment of prototrophic conidia of A. nidulans with ultraviolet irradiation auxotrophic selection was achieved by the nystatin method.