Morphological changes of conidiophores and mycelium of some hyphomycetes.

Abstract

The formation of enlarged cells and other abnormalities of mycelium and conidiophores occurring inAspergillus flavus Link,Penicillium chrysogenum Thom,Penicillium notatum Westling,Penicillium variabile Sopp.,Scopularipsis brevicaulis Bainier,Fusarium moniliforme Sheld.,Botrytis cinera Pers. ex Fr.,Botrytis allii Rud.,Humicola brunnea var.africana Fass. andTritirachium heimii var.grisea Fass. under the influence of uranium acetate, radioactive sediment from Přibram mines (uranium mines in Přibram, Bohemia), fungicidal compounds (fungizon, fungistatin, nitrofungin), antibiotic nystatin and antifungal bacteriumBacillus subtilis Cohn emend. Prazmowski were investigated. Enlarged phialides or phialides with extended orifices and collarettes and occasionally a conversion of phialides to spherical enlarged cells were observed inAspergillus flavus grown on a Sabouraud agar supplemented with uranium acetate. InPenicillium chrysogenum some conidiophores were completely reduced to enlarged cells. Less abnormalities were observed on the Czapek-Dox agar. The radioactive sediment as a component of malt agar caused either complete reduction of conidiophores inAspergillus flavus to dichotomously branched hyphae or sometimes only an enlargement of phialides. The antifungal effect ofBacillus subtilis was demonstrated in all studied strains. Enlarged cells instead of whole conidiophores were formed under the influence of the bacterium. This effect was observed inBotrytis allii, Botrytis cinerea and to a lesser extent inPenicillium notatum, Aspergillus flavus andFusarium moniliforme. The enlarged cells could still germinate and can be considered as reduced conidiophores. The used fungicidal compounds and the antibiotic nystatin inhibited to a certain degree the studied strains, however, their application did not bring about any abnormalities of mycelium and conidiophores.