Production of antifungal and antibacterial substances by fungi; preliminary examination of 166 strains of fungi imperfecti by p. W. Brian and h. G. Hemming citation
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hundred and sixty-six strains of Fungi Imperfecti have been examined primarily for the production of antifungalsubstances,though antibacterial substances have also been sought in most cases.
Antifungal substances were produced by several species of Aspergillus and Penicillium, Fusarium caeruleum, Metarrhizium glutinosum, Stachybotrys atra, Tri- choderrna viride, Gliocladium catenulatum and Trichothecium roseum. Antibacterial substances were produced by species of Aspergillus, Fusarium, Penicillium, Stachy- botrys and Trichoderma.
The chemical nature of the substances responsible for this activity is known or can be suggested in some cases, but others are worthy of further investigation.
Several surveys of the production of antibacterial substances by fungi have been published recently (Wilkins & Harris, 1942, 1943, 1944a, b, c; Wilkins, 1945, 1946; Robbins, Hervey, Davidson, Ma & Robbins, 1945),from which it appears that many of the Ascomycetes, Basidiomycetes and Fungi Im- perfecti show marked antibacterial activity but few, if any, of the Phyco- mycetes. No comparable surveys of the production of antifungal substances have been published, though many substances originally studied for their anti- bacterial activity have since been found to be also toxic to fungi. The present account deals with a number of Fungi Imperfecti examined primarily for anti- fungal activity; a preliminary examination for antibacterial activity has also been made in most cases. Species of Penicillium, Aspergillus and Trichoderma account for a high proportion of the strains examined, but representatives of seventeen other form-genera have been included. Further studies of certain of the strains found to produce antifungal substances have resulted in the isolation in pure form of the antibiotics viridin, glutinosin, gladiolic acid and ‘curling- factor’; the relevant references to this work are given in a later section of this paper.
EXPERIMENTAL MATERIALS AND METHODS
The fungi examined were obtained from various sources. Many were isolated in this laboratory from soils or other materials, and many were obtained from the National Collection of Type Cultures. The writers are also indebted to Dr G. R. Bisby for cultures of Trichoderma,Stachybotrys and Memnoniella and to Mr George Smith for cultures of Trichoderma and Gliocladium. All identifi- cations have been checked as far as possible