antimicrobial potential in the different tested assay media. Indeed,
the influence of nutritional factors on the production of biomass
and/or antifungal metabolites is well known and has been
described for several filamentous fungi such as Coniothyrium minitans
(McQuilken et al. 2010), Penicillium steckii (Sabat and Gupta
2011) or Lentinus tuberregium (Manjunathan and Kaviyarasan
2011). Environmental pH has also been described to influence
antifungal activity: an acidic pH showed to be important in stimulating
Coniothyrium minitans antifungal activity (Yang et al. 2008).
Accordingly, the highest H. fasciculare antimicrobial potential was
also obtained at the lowest pH value tested. However, pH alone cannot
explain the higher activity in PDA than in MMN media. When
comparing the antimicrobial activity using both media at almost
identical pH values (6.7 for PDA and 6.6 for MMN), the AP value
for the fungus grown on PDA medium (AP = 2.50) was almost twofold
higher than the one observed for the fungus grown on MMN
medium (AP = 1.32).
Altogether, the results suggest that the assay conditions for
performing this bioassay should be optimized for each pair of