Considerazioni ecologiche su alcuni geofunghi e idrofunghi

Abstract

Ecological considerations on some geofungi and hydrofungi. Some ecological aspects of the terrestrial and aquatic mycoflora are preliminarily examined, emphasizing in particular the ecological relations between fungi and environmental factors. The author adds a personal contribution based on his researches on the composition of Ticino river's fungal flora, controlled monthly in and around Pavia in the years 1973 and 1974, and on the quantitative production of aflatoxin B₁ by a toxinogenic strain of Aspergillus flavus in the presence of herbicides.

Yeasts represent the main component of the fungal flora of river waters, with a prevalence of Rhodotorula (R. rubra) in winter, Candida and Geotrichum in summer. In the zones of the river where industrial or urban discharges arrive, the population of yeasts is greater than in the North and South zone of the town. The data about the population of yeasts, chiefly of the genera Rhodotorula, Sporobolomyces and Candida, prove that these fungi are good biological indicators of contamination of a waterway.

As far as aflatoxins are concerned the author points out the stimulating influence of the herbicides Pyrazon (PCA) and Diuron (DMU) on the production of aflatoxin B₁.