Stress responses of fungal species to vanadium

Soil is a non-­renewable resource for human beings and ecosystems.Fungi have important roles in soil and can survive in high concentrations of toxic elements. The potentially toxic elements(PTEs) pose a significant threat on the human health.We investigated relationships between two fungal species,Penicillum citrinum and Paecilomyces lilacinus, isolated from soil with high levels of PTEs and vanadium. These speciesrevealed a tolerance to concentrations up to 6 mM, in relationto growth responses, bioaccumulation and mineraltransformation. Results were based on growth measurements,(GM), tolerance index (TI), scanning electron microscopy (SEM),energy dispersion X-­ray microanalysis (EDXA) and biomassmetal concentrations determined by means of inductivelycoupled plasma mass spectrometry (ICP-MS). Two basidiomycetespecies, Trametes hirsuta and Fomes fomentarius, isolatedfrom unpolluted areas, were also tested. They were able togrown up to 12 mM vanadium and accumulate it to high concentrations: more than 4000 μg/g dry weight for F.fomentarius and 8000 μg/g for T. hirsuta. It was also observedthat vanadium had a stimulatory effect on the growth of F.fomentarius. One-way analysis of variance (ANOVA) and Pearson’scorrelation test were used to test the linearity hypothesis for allthe interactions. Tolerance mechanisms may explain the occurrenceof fungi in metal-polluted habitats and provide opportunities forbioremediation.