STUDIES ON ASPERGILLI: XVIII. ESSENTIALITY OF TRACE ELEMENTS TO FIVE CONIDIAL ASPERGILLUS SPECIES

Abstract

The effect of zinc, iron, copper, and manganese on growth, sporulation, and pigmentation of Aspergillus sydowi (Bainier) Thom and Church, A. candidus Link, A. flavus Link, A. carneus (van Teigh) Bloch., and A. flavipes (Bainier and Sartory) Thom and Church was examined in a chemically defined medium under controlled conditions. The reduction in growth in cultures to which none of the above trace elements were added varied with the species. The essentiality of zinc, iron, copper, and manganese to most of the species under study was established. In manganese-deficient cultures, the fungal mats were wrinkled and in patches. The trace element deficiencies generally decreased the sporulation and modified the pigmentation of these aspergilli. Marked morphological changes in the conidiophores and vegetative hyphae were observed in cultures lacking all four trace elements.