Composting is a complex process in which various micro-organisms, mainly fungi and bacteria, are involved. The process depends on a large number of factors (biological, chemical, and physical) among which microbial populations play a fundamental role. The high temperatures that occur during the composting process indicate the presence of thermotolerant and thermophilic micro-organisms that are key for the optimization of the process. However, the same micro-organisms can be harmful (allergenic, pathogenic) for workers that handle large quantities of material in the plant, and for end users, for example, in the indoor environment (e.g., pots in houses and offices). Accurate knowledge of thermotolerant and thermophilic organisms present during the composting stages is required to find key organisms to improve the process and estimate potential health risks. The objective of the present work was to study thermotolerant and thermophilic mycobiota at different time points of compost maturation. Fungi were isolated at four temperatures (25, 37, 45, and 50 °C) from compost samples collected at five different steps during a 21-day compost-maturation period in an active composting plant in Liguria (northwestern Italy). The samples were subsequently plated on three different media. Our results showed a high presence of fungi with an order of magnitude ranging from 1 × 104 to 3 × 105 colony-forming units (CFU) g−1. The isolated strains, identified by means of specific molecular tools (ITS, beta-tubulin, calmodulin, elongation factor 1-alpha, and LSU sequencing), belonged to 45 different species. Several thermophilic species belonging to genera Thermoascus and Thermomyces were detected, which could be key during composting. Moreover, the presence of several potentially harmful fungal species, such as Aspergillus fumigatus, A. terreus, and Scedosporium apiospermum, were found during the whole process, including the final product. Results highlighted the importance of surveying the mycobiota involved in the composting process in order to: (i) find solutions to improve efficiency and (ii) reduce health risks.

Metal contamination constitutes a major source of pollution globally. Many recent studies emphasized the need to develop cheap and green technologies for the remediation or reclamation of environmental matrices contaminated by heavy metals. In this context, fungi are versatile organisms that can be exploited for bioremediation activities. In our work, we tested silver (Ag) bioaccumulation capabilities of three microfungal strains (Aspergillus alliaceus Thom & Church, Trichoderma harzianum Rifai, Clonostachys rosea (Link) Schroers, Samuels, Seifert & W. Gams) isolated from a silver polluted site. The aim was to select silver tolerant native strains and test their potential silver uptake. Among the three species tested, T. harzianum was the most efficient strain to tolerate and accumulate silver, showing an uptake capability of 153 mg L taken at the Ag concentration of 330 mg L. Our study highlights the potential use of native microfungi spontaneously growing in sulphide-rich waste rock dumps, for silver bioaccumulation and bioremediation.

Pesticides can help reduce yield losses caused by pests, pathogens, and weeds, but their 22 overuse causes serious environmental pollution. They are persistent in the environment and 23 are biomagnified through the food chain, becoming a serious health hazard for humankind. 24 Bioremediation, where microbes are used to degrade pesticides in situ, is a useful technology. 25 This review summarizes data on the fungi involved in the biodegradation of chemical 26 pesticides; and their application in soil and water bioremediation. Indications for future 27 studies in this field are given.

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Summary 1. Introduction. 1.1 Biodiversity in metal-contaminated sites. 1.2 Selecting native fungi and plants for bioremediation. 2. Case study – Multidisciplinary investigations on biodiversity into a sulphide-rich waste-rock dump. Conclusion: The enormous potential of native fungi and plants that are able to colonize metal-contaminated soils need to be studied in-depth in order to preserve the natural genetic resources of metalliferous habitats and to increase our basic knowledge about the natural adaptation mechanisms of hyperaccumulators in order to employ them in phytoremediation purposes

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Abandoned industrial sites and mines may constitute possible hazards for surrounding environment due to the presence of toxic compounds that may contaminate soils and waters. The possibility to remove metal contaminants, specifically nickel (Ni), by means of fungi was presented exploiting a set of fungal strains isolated from a Ligurian dismissed mine. The achieved results demonstrate the high Ni(II) tolerance, up to 500 mg Ni l, and removal capability of a Trichoderma harzianum strain. This latter hyperaccumulates up to 11,000 mg Ni kg, suggesting its possible use in a bioremediation protocol able to provide a sustainable reclamation of broad contaminated areas.

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