Brine shrimp and conductimetric Saccharomyces cerevisiae bioassays were used to investigate the toxicity of green barley malt prepared at 16 and 25°C from grain inoculated with a strain of Aspergillus clavatus known to produce the mycotoxins cytochalasin E and patulin during malting. Pure cytochalasin E was considerably more toxic to brine shrimp larvae than patulin (LC50 < 0.5 versus >30 µg ml-1). In contrast, patulin significantly inhibited growth-related change in conductance of S. cerevisiae cultures at a concentration of 10 µg ml-1, but cytochalasin E had no effect at 80 µg ml-1. Extracts of both 16 and 25°C malts contaminated with A. clavatus were toxic to brine shrimp larvae, but had only limited inhibitory effects on the growth of S. cerevisiae. Since concentrations of cytochalasin E in contaminated malts produced at 16°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.
- Aspergillus clavatus
- Cytochalasin E