Enrichment of Mutants of Mucor racemosus by Differential Freeze-killing

Publisher Website
Google Scholar
Abstract
An efficient technique for the enrichment of mutants of M. racemosus by differential freeze-killing is described. Ungerminated spores were resistant to freeze-killing. During germination susceptibility increased up to a maximum coinciding with the appearance of germ tubes. Under optimum conditions a 1000-fold preferential survival of growth-limited spores over actively germinating spores was obtained. Using this differential killing, cultures treated with mutagen were enriched with respect to auxotrophic and temperature-sensitive mutants, with the desired mutants constituting a large fraction of the survivors of the freeze-thaw treatments. This technique may be applicable to mutant enrichment in other filamentous fungi.