Antimycotic Activity of Fungi Isolated from Hawaiian Soils

SUMMARY

The fungus populations of 61 forest and 39 cultivated soils from Oahu, Hawaii, were screened for antimycotic activity in vitro against 5 fungi displaying various levels of pathogenicity for man. Antimycosis occurred in fungi from the two sources in approximately equal distribution. For in vitro assay both broth and mycelial extracts were used against the test fungi. By these assays 175 isolates displayed antimycotic activity in mycelium, broth, or both. Antimycosis was shown by 6 Phycomycetes, 3 Ascomycetes, 30 Aspergilli, 49 Penicillia, 25 Fusaria, 47 other Fungi Imperfecti, and 15 non-sporulating isolates. A number of species not previously reported as sources of antimycotic substances were found. Only a few species were capable of antimycosis against all 5 test organisms but among these was Cunninghamella echinulata. Other Phycomycetes produced significant levels of inhibition. It is suggested that Hawaiian soils are a good source of antimycotic substances of potential therapeutic value and that the Phycomycetes as a group should be reexamined for antimycosis.