A Dactylium dendroides morphological mutant defective in D-galactose metabolism

1. A morphological mutant of the mold Dactylium dendroides was and the phenotype characterized as D-Gal-and L-Ara-. 2. The transport system for D-galactose seemed to be inducible in wild type and mutant and was altered in the mutant. 3. Galactose-1-P- uridylyl transferase activity was absent in the mutant. 4. The levels of intracellular galactose oxidase activity were similar in the wild type and in the mutant, theraby excluding a possible participation of this enzymes in glactose catabolism inthe mold. 5. The low level of galactose oxidase activity found in the extracellular medium indicates a defect in galactose oxidase secretion by the mutant