Nutrition and Parasitism of Melanospora zamiae

Abstract

SUMMARYMelanospoa zamiae was shown to be a biotrophic contact mycoparasite. It produced hook-shaped branches when contact was made with host hyphae. The hook-shaped branches completely or partially surrounded the host hyphae but did not invade the host cell. The parasite was able to obtain all nutrients necessary for growth and sporulation from washed living mycelia of host fungi separated from the culture medium. The required nutrients were held within the host mycelium and were not excreted into the culture medium. The host range included eleven species of Ascomycetes and Deuteromycetes. Melanospora zamiae was deficient for thiamine and biotin but not the growth factor mycotrophein, which it synthesized. The addition of zinc to a glucose 10-casein hydrolysate 2 liquid medium supplemented with thiamine and biotin was required for maximum axenic growth and sporulation. D-glucose, D-fructose, D-mannose and cellobiose were the best sources of carbon. The nitrogen sources casein hydrolysate, L-asparagine, L-aspartic acid, L-alanine, L-glutamic acid and urea were utilized to the greatest degree.