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

Interactions of Penicillium griseofulvum with inorganic and organic substrates: vanadium, lead and hexachlorocyclohexane.

Soil is an essential and non-renewable resource for human beings and ecosystems. In recent years, anthropogenic activities mainly related to hydrocarbon fuel combustion, mining and industrial activities have increased the levels of vanadium in the environment, raising concern over its spread. Vanadium may be essential for some bacteria and fungi, but can have toxic effects at high concentrations. The pesticide lindane or γ-hexachlorocyclohexane (γ-HCH) and another two isomers of hexachlorocyclohexane (HCH), α-HCH, and β-HCH, were included as persistent organic pollutants in the Stockholm Convention in 2008, and their worldwide spread and toxic effects on organisms are severe environmental problems. Fungi play important roles in soil and can survive in high concentrations of toxic elements and pesticides by possessing mechanisms for the degradation, utilization and transformation of organic and inorganic substrates. The transformation of potentially toxic elements (PTEs), and degradation of chlorinated pesticides and other persistent organic pollutants may provide environmentally-friendly and economical approaches for environmental management and restoration. In this work, we have investigated the tolerance of a soil fungal species, Penicillum griseofulvum, to different hexachlorocyclohexane (HCH) isomers, α-HCH, β-HCH, δ-HCH and γ-HCH or lindane, and two PTEs, vanadium and lead in relation to growth responses and biotransformation. P. griseofulvum was isolated from soils with high levels of PTEs (including vanadium and lead), and HCH residues. P. griseofulvum was able to tolerate vanadium concentrations up to 5 mM, combinations of 2.5 mM vanadium and lead compounds, and was able to grow in the presence of a 4 mg L-1 mixture of α-HCH, β-HCH, δ-HCH and γ-HCH, and degrade these substrates. Tolerance mechanisms may explain the occurrence of fungi in polluted habitats: their roles in the biotransformation of metals and persistent organic pollutants may provide opportunities for bioremediation