To identify the actinobacterial isolate with the greatest inhibition potential, a factorial experiment (1 × 1) was performed. The F-value was highly significant (p < 0.01), demonstrating a similar inhibition potential of 12 out of the 13 isolates tested. The only isolate that showed a lower inhibitory efficiency was AD G31 13A 69 (Streptomyces globisporus subsp. globisporus). Fungal strains 03/830-09A3 (Cladosporium sp.) and 40/952-09B3 (Exophiala pisciphila) were more efficiently inhibited by the actinobacteria assayed than the other fungal isolates.