MYCOTOXINS OF ASPERGILLUS-CLAVATUS - TOXICITY OF CYTOCHALASIN-E, PATULIN, AND EXTRACTS OF CONTAMINATED BARLEY MALT

Brine shrimp and conductimetric Saccharomyces cerevisiae bioassays wer e used to investigate the toxicity of green barley malt prepared at 16 and 25 degrees C from grain inoculated with a strain of Aspergillus c lavatus known to produce the mycotoxins cytochalasin E and patulin dur ing malting. Pure cytochalasin E was considerably more toxic to brine shrimp larvae than patulin (LC50 < 0.5 versus >30 mu g ml(-1)). In con trast, patulin significantly inhibited growth-related change in conduc tance of S. cerevisiae cultures at a concentration of 10 mu g ml(-1), but cytochalasin E had no effect at 80 mu g ml(-1). Extracts of both 1 6 and 25 degrees C malts contaminated with A. clavatus were toxic to b rine shrimp larvae, but had only limited inhibitory effects on the gro wth of S. cerevisiae. Since concentrations of cytochalasin E in contam inated malts produced at 16 degrees C are below or close to the limits of detection, the presence of other fungal metabolites toxic to brine shrimps in such malts is indicated.