title: Assessment of the applicability of a "toolbox" designed for microbially assisted phytoremediation: the case study at Ingurtosu mining site (Italy).
abstract: The paper describes the fieldwork at the Italian test site of the abandoned mine of sphalerite and galena in Ingurtosu (Sardinia), with the aim to assess the applicability of a "toolbox" to establish the optimized techniques for remediation of soils contaminated by mining activities. A preliminary characterization-including (hydro)geochemistry, heavy metal concentration and their mobility in soil, bioprospecting for microbiology and botany-provided a data set for the development of a toolbox to deliver a microbially assisted phytoremediation process. Euphorbia pithyusa was selected as an endemic pioneer plant to be associated with a bacterial consortium, established with ten selected native strains, including metal-tolerant bacteria and producers of plant growth factors. The toolbox was firstly assessed in a greenhouse pot experiment. A positive effect of bacterial inoculum on E. pithyusa germination and total plant survival was observed. E. pithyusa showed to be a well-performing metallophyte species, and only inoculated soil retained a microbial activity with a high functional diversity, expanding metabolic affinity also towards root exudates. These results supported the decision to proceed with a field trial, investigating different treatments used singly or in combination: bioaugmentation with bacterial consortia, mycorrhizal fungi and a commercial mineral amendment. Microbial activity in soil, plant physiological parameters and heavy metal content in plants and in soil were monitored. Five months after the beginning, an early assessment of the toolbox under field conditions was carried out. Despite the cold season (October-March), results suggested the following: (1) the field setup as well as the experimental design proved to be effective; (2) plant survival was satisfactory; (3) soil quality was increased and bioaugmentation improved microbial activity, expanding the metabolic competences towards plant interaction (root exudates); and (4) multivariate analysis supported the data provided that the proposed toolbox can be established and the field trial can be carried forward.
authors.affiliation: Environmental Characterization, Prevention and Recovery Unit, Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Via Anguillarese, 301-00123, Rome, Italy.
authors.forename: Anna Rosa
authors.initials: AR
authors.lastname: Sprocati
authors.forename: Chiara
authors.initials: C
authors.lastname: Alisi
authors.forename: Valentina
authors.initials: V
authors.lastname: Pinto
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Montereali
authors.forename: Paola
authors.initials: P
authors.lastname: Marconi
authors.forename: Flavia
authors.initials: F
authors.lastname: Tasso
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Turnau
authors.forename: Giovanni
authors.initials: G
authors.lastname: De Giudici
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Goralska
authors.forename: Marta
authors.initials: M
authors.lastname: Bevilacqua
authors.forename: Federico
authors.initials: F
authors.lastname: Marini
authors.forename: Carlo
authors.initials: C
authors.lastname: Cremisini
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D028481:Euphorbia / Q000254:growth & development* / Q000378:metabolism / Q000382:microbiology; D005658:Fungi / Q000378:metabolism; D007558:Italy; D019216:Metals, Heavy / Q000032:analysis*; D008906:Mining; D015999:Multivariate Analysis; D038821:Mycorrhizae / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants