Evidence of pyrite dissolution by Telephora terrestris Ehrh in the Libiola mine (Sestri Levante, Liguria, Italy)

Evidence of pyrite dissolution by Telephora terrestris Ehrh were observed for the first time in the abandoned sulphide Libiola mine in May 2017 (Sestri Levante, Liguria, Italy). This fungus is an ectomycorrhizal species able to colonize this extreme environment and bioaccumulate metals such as copper and silver in its fruiting bodies, and it is known to establish symbiosis with maritime pines present in the area, thus favouring their recolonization of the site. This paper presents evidence of T. terrestris promoted dissolution of sulphide minerals. This species can remove from soil not only metals possibly toxic to the pine trees, but it can also contribute to the ions bioaccumulation through the bioweathering of sulphide mineral grains (especially pyrite)

Sulfide weathering processes mediated by microfungi

This study aimed to experimentally investigate the interactions, the bioalteration, and the biocorrosion of sulfides mediated by three microfungi (Trichoderma harzianum group, Penicillium glandicola, P. brevicompactum) isolated within the open-air waste-rock dumps from Libiola mine (Liguria, Italy). Unaltered samples of pyrite-mineralizations from the same waste-rock dumps were ground and sieved into size fraction of 150-63 \u3bc m which resulted composed by single crystals of pyrite (>80 wt%), with minor quartz and trace amount of chalcopyrite. The mineral bioalteration tests were carried out for six weeks using Czapek-Dox agar medium (CZA). In each plate, four pyrite crystals or crystal fragments were set into the solid medium. After one week, pyrite grains were almost completely covered by mycelia of the three different fungi. The samples were examined, before and after the experimental procedure, using plane-polarized optical microscopy (transmitted- and reflected-light) and environmental scanning electron microscopy (ESEM-EDS). The ESEM analyses were performed in low-vacuum mode for the micromorphological analyses to characterize the evolution of the mineralfungi interactions during the different experimental steps. After six weeks covered by mycelia, the pyrite grains were collected and analyzed revealing that the surface of pyrite crystals was strongly corroded in all experimental tests. ESEM images underlined how pyrite alteration was strictlty associated with biological patterns (curves, rounded cracks, and sinuous traces). Corrosion patterns and etching pits were not related to specific crystallographic planes or weakness, but were randomly distributed on the crystal surfaces, in particular in correspondence of the fungal hyphae attachment. Moreover, in the same temporal interval, the control experiment performed in abiotic conditions did not show any dissolution evidences thus suggesting that in absence of fungal interactions the pyrite weathering did not occur or was much slower. The experimental results evidenced the active role of fungi in the pyrite crystal weathering and suggested that sulfide alteration was not only the consequence of the interactions between metabolites secreted by fungi and minerals, but there was also a possible bio-mechanical role of hyphae in corrosion through penetration, boring, and burrowing along weak crystal planes or microfractures. Finally, the evidences of biocorrosion led to evaluate the important role of fungi in the iron and sulfur cycles in sulfide-bearing materials, since fungal alteration systematically triggers sulfide to sulfate oxidation, causing local gypsum and Fe-oxyhydroxides precipitation within mycelium structure

Applied Tests to Select the Most Suitable Fungal Strain for the Recovery of Critical Raw Materials from Electronic Waste Powder

Electrical and electronic wastes (WEEEs) are a potential source of raw materials. The main challenge for scientists is to set up a reliable and eco-friendly process to recycle raw materials and precious elements from WEEEs. Today, we know that fungi could play an active role in green technologies aimed at recycling valuable elements. The bioaccumulation mechanism and bioleaching activity of filamentous fungal species have already been exploited fruitfully in extraction processes. However, not all fungal strains possess the same characteristics, and it is crucial to choose the right strains to use. In this work, we show a method to assess the precious elements’ recovery efficiency from WEEE using fungal strains. A CAS agar screening test for siderophore detection was carried out with three strains. The following plate accumulation test performed on a medium added with 120 ppm of electronic waste powder highlighted the differences in accumulation capability, growth rate, and biomass production. Among the elements in tested waste, yttrium, copper, and palladium show the highest bioconcentration factor. The results confirm the biotechnological potential of fungi to recover valuable elements at the bench scale, highlighting the importance of effective screening tests to assess the most efficient strain for each kind of waste

Can the soil geology and chemistry analysis of a site predict the geographic origin of wild edible mushrooms (Porcini group)?

This study aimed to assess the element content of Porcini mushrooms collected from broadleaf Mediterranean forests (NW Italy) and underlying soil layers, and to elucidate the chemical connection between the mushrooms and their geographic site of origin. Comparing the elements in mushrooms with those in soil samples, we observed that the concentration of some microelements detected in mushrooms had similar distribution as that measured in both the soil layers assessed, especially with surface soil. Statistical analyses showed that the microelement pattern in mushrooms reflects the soil site of origin. Moreover, by comparing our results with other studies, we observed that the soil where Porcini grow is characterized by a high concentration of zinc. Some toxic elements were also detected in mushroom samples. Analysis of elements in mushrooms and soil layers can be used for quality assurance of natural products and help distinguish them from uncertified and unknown-origin products

Use, Attitudes and Knowledge of Complementary and Alternative Drugs (CADs) Among Pregnant Women: a Preliminary Survey in Tuscany

To explore pregnant women's use, attitudes, knowledge and beliefs of complementary and alternative drugs (CADs) defined as products manufactured from herbs or with a natural origin. A preliminary survey was conducted among 172 pregnant women in their third trimester of pregnancy, consecutively recruited in two obstetrical settings; 15 women were randomly selected to compute a test-to-retest analysis. Response rate was 87.2%. Test-to-retest analysis showed a questionnaire's reproducibility exceeding a K-value of 0.7 for all items. Mean age was 32.4 ± 0.4 years; most women were nulliparae (62.7%). The majority of subjects (68%) declared to have used one or more CADs during their lifetime; 48% of pregnant women reported taking at least one CAD previously and during the current pregnancy. Women's habitual use of CADs meant they were at higher risk of taking CADs also during pregnancy (adjusted odds ratio = 10.8; 95% confidence interval: 4.7–25.0). Moreover, 59.1% of the subjects were unable to correctly identify the type of CADs they were using. The majority of women resorted to gynecologists as the primary information source for CADs during pregnancy, while they mainly referred to herbalists when not pregnant. Habitual use of CADs seems to be a strong predictor for their ingestion also during pregnancy; in addition most subjects were unable to correctly identify the products they were taking. In the light of the scanty data concerning the safety of CADs during pregnancy, these preliminary results confirm the need to investigate thoroughly the situation of pregnant women and CADs consumption

An annotated checklist of macrofungi in broadleaf Mediterranean forests (NW Italy)

Three different broadleaf Mediterranean forests, each characterized by the dominance of Castanea sativa, Quercus cerris, and Fagus sylvatica, respectively, were intensively surveyed over 3 consecutive years to record a list of macrofungi. A total of 5,065 sporomata and 300 species (seven Ascomycota and 293 Basidiomycota) belonging to 18 orders, 59 families, and 117 genera were recorded. The ecology, community composition, and geographic distribution of the identified species are discussed and new records for Italy are also provided