Comparative Toxicity Assessment of Soil Fungi Isolated from Black Sea Coasts

The research was aimed to compare the soil fungal communities of the Black Sea north and south coasts and to evaluate the toxicity of fungi isolated in these areas. General toxicity of the fungi identified was evaluated by P. caudatum bioassay and skin test bioassay on rabbits. There is no significant difference in the total fungal counts in soil samples taken in the Black Sea north and south coasts, being 3.18–3.50 CFU*103 g−1 dry soil. Cultures of the fungi genera such as Aspergillus, Penicillium, Fusarium, Mucor, Rhodotorula, and Trichoderma were isolated using methods of mycology. Soil fungal isolated from north coast samples were found to be nontoxic (79.2–81.2% of paramecia survived) in P. caudatum biotesting, while those isolated from south coast ones being slightly toxic (65.6–69.4%) (p < 0.05). Some fungal isolates from north coast samples also had no toxic effect on the Paramecia. Three fungal isolates from the south coast were slightly toxic, with the survival rate of test organisms being 55.33–62.67%. Only one isolate of the species A. flavus, A. fumigatus, and F. sporotrichioides each was found to have a toxic effect in the Paramecia. The toxicity of these fungal isolates was confirmed with a rabbit bioassay. The results obtained give evidence to grade 1 toxicity in 24 h after applying the suspension prepared from the mycelial mat of A. flavus and F. sporotrichioides isolated from the south coast. The rabbit skin test bioassay demonstrated also the A. fumigatus isolate from the south coast having grade 2 toxicity.