Discussion
A bioassay to detect the antimicrobial activity of filamentous
fungi against single-cell microorganisms was designed and
optimized using H. fasciculare as filamentous fungal model. S. cerevisiae
was tested and showed to be sensitive to the fungal action,
being thereafter used as sensitive indicator strain, but other yeasts
showed to be sensitive to this fungus too and could be used as tester
strains. H. fasciculare has been described as displaying antagonist
activity against other filamentous fungi (Boddy 2000; Badalyan
et al. 2002; Barret 2009), but antimicrobial activity against yeast
species has never been detected before.
Using this system, the antimicrobial activity was best detected
in PDA medium, after 6-days of fungal growth and using 106 CFU/ml
of the microbial indicator strain. Medium composition or nutritional
factors can underlie the differences regarding H. fasciculare