or growth in a liquid media previously used
by the fungal antagonist (Georgakopoulos et al. 2002) have been
currently used. Dual cultures are more commonly used for testing
fungal antagonism against other filamentous strains. However, this
method has the limitation of being dependent on the slow fungal
growth and requires time to detect antagonism. The use of liquid
media where the fungus to be tested for antimicrobial potential has
grown is usually exploited for testing antimicrobial activity against
bacteria or yeasts, but depends on the stability of the antimicrobial
compound(s) and is much time consuming.
Here we report a rapid, effective and reproducible assay for
determining the antimicrobial activity of filamentous fungi. The
novelty of this test lays in the use of actively growing mycelia
against a single cell microorganism as sensitive indicator strain,
instead of against another filamentous fungus. Used for testing the
in vivo fungal antimicrobial activity against single-cell organisms as
yeasts, it allows a faster and more reliable strategy than using the
partially purified antimicrobial compound. The herein described
bioassay was established and optimized using Hypholoma fasciculare
as the filamentous fungal model, a cord-forming basidiomycete
common among the saprophytic trophic group.
H. fasciculare antagonist activity towards other soil-borne fungi
has been already described (Nicolotti and Varese 1996; Nicolotti
et al. 1999; Woods et al. 2005), some of which parasitic (Chapman
et al. 2004; Cox and Scherm 2006). Recently, antibacterial activity
was also described (de Boer et al. 2010). Despite these reports on