STUDIES ON STACHYBOTRYS ALTERNANS

Abstract

Isolation of 73 Stachybotrys alternans strains from various materials, their morphological description and results from toxigenicity tests by a tissue culture method are reported. The isolation method consisted of culturing the material on wet cotton wool and sterile filter paper. Out of the 725 samples of cereal grain, field pea, oat meal, feed and fodder sent for routine mycological investigation 50 strains of S. alternans were isolated. Rather strikingly, approximately every fourth of the samples of field pea seed was found to be contaminated with S. alternans. Among the 129 samples of feed and fodder suspected as a cause of mycotoxicosis in domestic animals, 22 turned out to be contaminated by S. alternans. The toxicity of ether soluble extracts from strains cultivated on wheat‐oats‐barley mixture was tested in mouse primary fibroblast cultures. Together 49 out of the 73 isolated strains were found toxigenic by the test. All 13 strains isolated from field pea samples produced toxin. No relation between morphological characteristics and toxicity was revealed.