Stefano Fazi's research while affiliated with National Water Research Institute and other places

Publications (111)

Article
Active hydrothermal travertine systems are ideal environments to investigate how abiotic and biotic processes affect mineralization mechanisms and mineral fabric formation. In this study, a biogeochemical characterization of waters, dissolved gases, and microbial mats was performed together with a mineralogical investigation on travertine encrustat...
Article
Although terrestrial hydrothermal systems are considered among the most fascinating environments, how their unique and extreme conditions can affect microorganisms selection and the role in biogeochemical cycles has not yet been well elucidated. A combined geochemical and microbiological exploration in waters and sediments from ten sampling points...
Article
The present paper was aimed at investigating the role of disposable medical masks as a substrate for microbial biofilm growth and for the selection of specific microbial traits in highly impacted marine environments. In this view, we have immerged masks in a coastal area affected by a continuous input of artisanal fishery wastes and hydrocarbons po...
Book
Full-text available
This publication is an output from EU COST Action DNAqua-Net (CA 15219 - Developing new genetic tools for bioassessment of aquatic ecosystems in Europe) and would not have been possible without the opportunities for international collaboration provided by the network, supported by COST (European Cooperation in Science and Technology). Therefore, ou...
Article
The pressure placed on global water resources by landscape modification and various forms of pollution is being exacerbated by climate change. While substantial progress has been observed in the field of wastewater treatment, less attention has been given on how to reduce the impact of diffuse sources such as runoff from agriculture and urban areas...
Article
Full-text available
Environmental DNA (eDNA) metabarcoding (parallel sequencing of DNA/RNA for identification of whole communities within a targeted group) is revolutionizing the field of aquatic biomonitoring. To date, most metabarcoding studies aiming to assess the ecological status of aquatic ecosystems have focused on water eDNA and macroinvertebrate bulk samples....
Article
In this work, an untargeted approach based on ultra-high performance liquid chromatography coupled to high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) was employed for the analysis of contaminants in surface water samples, possibly deriving from an ineffective removal by wastewater treatment plants or illicit release. First, solid-phase ext...
Article
Full-text available
The contribution of oxic methane production to greenhouse gas emissions from lakes is globally relevant, yet uncertainties remain about the levels up to which methanogenesis can counterbalance methanotrophy by leading to CH4 oversaturation in productive surface waters. Here, we explored the biogeochemical and microbial community variation patterns...
Article
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Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better healt...
Article
Full-text available
Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better healt...
Article
Full-text available
Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better healt...
Article
Full-text available
Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better healt...
Article
Full-text available
Arsenic mobilization in groundwater systems is driven by a variety of functionally diverse microorganisms and complex interconnections between different physicochemical factors. In order to unravel this great ecosystem complexity, groundwaters with varying background concentrations and speciation of arsenic were considered in the Po Plain (Northern...
Article
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Bioindication has become an indispensable part of water quality monitoring in most countries of the world, with the presence and abundance of bioindicator taxa, mostly multicellular eukaryotes, used for biotic indices. In contrast, microbes (bacteria, archaea and protists) are seldom used as bioindicators in routine assessments, although they have...
Article
Full-text available
Microbial communities are major players in the biogeochemical processes and ecosystem functioning of river networks. Despite their importance in the ecosystem, biomonitoring tools relying on prokaryotes are still lacking. Only a few studies have employed both metabarcoding and quantitative techniques such as Catalyzed reported deposition fluorescen...
Article
Full-text available
Little is known about the quantity and quality of dissolved organic matter (DOM) in waters from continental geothermal systems, with only a few reports available from the Yellowstone US National Park. In this study, we explored the chemodiversity of DOM in water samples collected from two geothermal hot springs from the Kenyan East African Rift Val...
Article
Urban lakes have become increasingly important in the planning of urban ecology, green infrastructure and green areas in European cities. This paper describes the chemical, isotope and microbial features of Lake Bullicante, a small artificial lake located within the urban area of the city of Rome. It has an anthropogenic origin due to excavation wo...
Article
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Marine organisms produce a vast diversity of metabolites with biological activities useful for humans, e.g. cytotoxic, antioxidant, anti-microbial, insecticidal, herbicidal, anticancer, pro-osteogenic and pro-regenerative, analgesic, anti-inflammatory, anti-coagulant, cholesterol-lowering, nutritional, photoprotective, horticultural or other benefi...
Conference Paper
Lago Exsnia-Viscosa is located in the eastern part of Rome, on the left bank of Tiber river, close to the historical centre of the city and in a highly urbanized area. The lake takes its name from the factory of artificial silk, the SNIA Viscosa, active there from 1923 to 1954. The industrial plant, located close to the Marranella ditch, used its w...
Article
Saline-alkaline lakes of the East African Rift are known to have an extremely high primary production supporting a potent carbon cycle. To date, a full description of carbon pools in these lakes is still missing. More specifically, there is not detailed information on the quality of dissolved organic matter (DOM), the main carbon energy source for...
Article
Quorum sensing signals regulate various functions within activated sludge processes such as formation of microbial aggregates. Disturbance of this signaling system, known as quorum quenching (QQ), provides opportunities for eliminating some problems related to biological wastewater treatment (e.g., biofouling and excess sludge production). However,...
Article
Glyphosate-based herbicides are widely used for several crops, such as transgenic soybean and forestry. The aim of this study was to determine the effect of glyphosate on the community structure of riverine bacterioplankton and to evaluate the potential of bacterioplankton to degrade the herbicide. River water to which 13C-labelled glyphosate (10,...
Article
The influence of the freshwater runoff on marine prokaryotes has been largelly studied in the pelagic environment, little is known about the effects on the prokaryotes in coastal sediments. We investigated the distribution of benthic prokaryotes in the northern Adriatic Sea, when an extreme Po River flood event determined high heterogeneity along t...
Poster
This study provided the detailed description of structural and metabolic traits of native microbial communities in arsenic-rich freshwaters and associated with biofilm. The diversity of As-related functional genes was also explored as well as the main microbial functional groups occurring in the geothermal environments herein analysed. The arsenic...
Article
Full-text available
Direct and indirect effects of extremely high geogenic CO 2 levels, commonly occurring in volcanic and hydrothermal environments, on biogeochemical processes in soil are poorly understood. This study investigated a sinkhole in Italy where long-term emissions of thermometamorphic-derived CO 2 are associated with accumulation of carbon in the topsoil...
Conference Paper
Full-text available
Volcanic lakes are characterized by physicochemical favorable conditions for the development of reservoirs of greenhouse gases that can be dispersed to air during occasional rollover events. By combining a microbiological and geochemical approach, we showed that the chemistry of the CO2-and CH4-rich gas reservoir hosted within the meromictic Lake A...
Conference Paper
Lago Ex-Snia is a small lake in the eastern sector of the urban area of Rome. It has an anthropogenic origin related to a great urban speculation of the '90s that, in the attempt to illegally build a shopping center, brought the underlying aquifer to be intercepted, giving rise to a mirror of water: Lago Ex-Snia. The lake is 10.000 mq large, around...
Article
To understand to what extent depositional dynamics and riverine input contribute to shape the microbial benthic community structure in coastal systems, surface sediments were collected along one nearshore and two land-sea transects in the Po River prodelta, and analyzed for lithology, sediment structures, grain-size, short-lived radioisotopes (7Be...
Article
Microbial electrochemical technologies (METs) represent a novel platform to harvest the energy trapped in municipal wastewater. At the anode of METs, electro‐active bacteria (EAB) anaerobically oxidize wastewater constituents using the electrode as the terminal electron acceptor and, by so doing, generate an electric current. To convert complex was...
Article
This study represents the first example in which benthic heterotrophic and photoautotrophic microbial communities (prokaryotes and microphytobenthos-MPB, respectively) were simultaneously investigated. To explore how they synergistically respond to multiple natural and anthropogenic stressors, in the framework of the Project RITMARE four lagoons of...
Conference Paper
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Biogeochemical sampling was carried out at Sonachi Crater Lake, a small (0.18 km 2) soda lake of volcanic origin located within the Eastern Rift Valley, 90 km NW of Nairobi (central Kenya), immediately southwest of lake Naivasha. The lake is protected from winds by steep crater walls and the water level is regulated by rainfall, very limited runoff...
Article
Arsenic (As) contamination in drinking water represents a worldwide threat to human health. During last decades, the exploitation of microbial As-transformations has been proposed for bioremediation applications. Among biological methods for As-contaminated water treatment, microbial As(III)-oxidation is one of the most promising approaches since i...
Article
Microbial electrochemical systems (MES) represent an innovative reagent-free technology for in situ remediation of groundwater contaminated by petroleum hydrocarbons. Here we describe the long-term (>160 days) anaerobic treatment of a synthetic groundwater containing toluene (25 mg/L) in a novel laboratory-scale, continuous-flow bioelectrochemical...
Article
An integrated geochemical and microbiological investigation of soils from the Solfatara Crater (Campi Flegrei, southern Italy) demonstrated that interstitial soil gases dominated by CO2 and other typical hydrothermal gaseous species (e.g. H2S, CH4, ethane, benzene, alkenes and S-bearing organic compounds) influenced the composition of microbial com...
Conference Paper
Arsenic(As) is one of the most toxic element worldwide. Despite As toxicity, many microorganisms evolved different mechanisms to metabolize it and withstand high concentrations, thus revealing the microbial potentiality in bioremediation applications. Microbiological As(III)-oxidation is one of the most promising application as a precursor step in...
Conference Paper
Arsenic (As) represents a worldwide threat to human health. Despite As toxicity, many microorganisms evolved different mechanisms to metabolize it and withstand high concentrations, thus revealing the microbial potentiality in bioremediation applications. Among biological methods for As-contaminated water treatment, microbial As(III) oxidation is o...
Poster
Arsenic (As) is one of the most toxic and widely distributed element in the environment. Aquatic microorganisms are able to resist to high As concentration and/or metabolize it, with metabolic potentialities suitable for biotechnological applications. In particular, microbiological As(III)-oxidation is one of the most promising application as a pre...
Conference Paper
Arsenic a semi-metallic element found naturally in ground water in some areas of India, Bangladesh, Italy, Chile, China, Argentina, Mexico, and many other countries. Due to differences in geochemistry, environmental conditions, and human activities, arsenic concentration in ground water aquifers varies widely which is several times higher than Maxi...
Conference Paper
The presence of high arsenic concentration in water for human consumption posed serious health risks to millions of people in the world, requiring the installation of removal plants. This led to a significant increased amount of As-rich waste, mainly iron based sludge and exhausted filtering materials. Environmental impact of the produced waste mat...
Preprint
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Flow cytometry is suitable to discriminate and quantify aquatic microbial cells within a spectrum of fluorescence and light scatter signals. Using fixed operational and gating settings, a mixture model, coupled to Laplacian operator and Nelder-Mead optimization algorithm, allowed deconvolving bivariate cytometric profiles into single cell subgroups...
Conference Paper
Full-text available
Benthic communities inhabiting river lagoons are subjected to several natural (e.g. hypoxia and anoxia events) and anthropogenic disturbances such as excessive organic and nutrient loads from urban, industrial and agricultural discharges and high contamination levels. To investigate how benthic microbial communities (prokaryotes and microphytobenth...
Data
Operational taxonomic units (OTUs) relative abundance in water samples estimated by NGS. (PDF)
Article
Full-text available
Volcanic lakes are characterized by physicochemical favorable conditions for the development of reservoirs of C-bearing greenhouse gases that can be dispersed to air during occasional rollover events. By combining a microbiological and geochemical approach, we showed that the chemistry of the CO2- and CH4-rich gas reservoir hosted within the meromi...
Article
Flow cytometry is suitable to discriminate and quantify aquatic microbial cells within a spectrum of fluorescence and light scatter signals. Using fixed gating and operational settings, we developed a finite distribution mixture model, followed by the Voronoi tessellation, to resolve bivariate cytometric profiles into cohesive subgroups of events....
Article
Full-text available
Background Recent studies have suggested that addition of electrically conductive biochar particles is an effective strategy to improve the methanogenic conversion of waste organic substrates, by promoting syntrophic associations between acetogenic and methanogenic organisms based on interspecies electron transfer processes. However, the underlying...
Article
Full-text available
Arsenic (As) is a toxic element released in aquatic environments by geogenic processes or anthropic activities. To counteract its toxicity, several microorganisms have developed mechanisms to tolerate and utilize it for respiratory metabolism. However, still little is known about identity and physiological properties of microorganisms exposed to na...
Article
Full-text available
Understanding DOM transport and reactivity in rivers is essential to having a complete picture of the global carbon cycle. In this study, we explore the effects of hydrological variability and downstream transport on dissolved organic matter (DOM) dynamics in a Mediterranean river. We sampled the main stem of the river Tordera from the source to th...
Article
Full-text available
Groundwater plays a central role in the hydrological cycle and represents the utmost natural resource for human consumption and activities on a global scale. Therefore, any source of contamination of either geogenic or anthropogenic origin may provide a serious environmental health threat. Within the long list of organic and inorganic groundwater c...
Article
Full-text available
Sediment resuspension represents a key process in all natural aquatic systems, owing to its role in nutrient cycling and transport of potential contaminants. Although suspended solids are generally accepted as an important quality parameter, current monitoring programs cover quantitative aspects only. Established methodologies do not provide inform...
Conference Paper
Full-text available
Volcanic and hydrothermal areas represent extreme environments, being affected by high-temperature and low-pH fluid emissions. Microbial life develops in such a harsh and spatially rapidly changing environment, affecting and being affected by the local geochemical conditions. Whilst efforts have been made to investigate the interaction between biot...
Conference Paper
Full-text available
Soils in volcanic and hydrothermal areas are affected by anomalously high concentrations of gases released from the deep reservoirs, which consists of both inorganic (mainly CO2 and H2S) and organic (volatile organic compounds ; VOCs) species. VOCs in volcanic and hydrothermal fluids are mainly composed of saturated and unsat-urated hydrocarbons (a...
Article
Different countries in Europe still suffer of elevated arsenic (As) concentration in groundwaters used for human consumption. In the case of households not connected to the distribution system, decentralized water supply systems, such as Point of Use (POU) and Point of Entry (POE), offer a direct benefit for the consumers. Field scale ex-situ treat...
Article
The Po River runoff strongly affects the oceanographic and ecological characteristics of the Northern Adriatic Sea. Catalysed reported deposition - fluorescence in situ hybridization (CARD-FISH) analysis was employed to assess how the composition of the coastal bacterioplankton community is influenced by the river runoff in two different seasons (s...
Article
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The protection, preservation and restoration of aquatic ecosystems and their functions are of global importance. For European states it became legally binding mainly through the EU-Water Framework Directive (WFD). In order to assess the ecological status of a given water body, aquatic biodiversity data are obtained and compared to a reference water...
Poster
Arsenic (As) is one of the most toxic elements widely distributed in natural environments. It can exist in four oxidation states (+V, +III, 0, -III) and exhibit different mechanisms of toxicity to the biota, with AsIII more toxic than AsV. Microorganisms have developed mechanisms to tolerate and/or utilize As for respiratory metabolism. This work i...
Article
Full-text available
Uncertainties exist regarding the magnitude of in situ dissolved organic matter (DOM) processing in lotic systems. In addition, little is known about the effects of extreme hydrological events on in-stream DOM retention or release during downriver transport. This study quantified the net in-stream retention/release efficiencies (η) of dissolved org...
Article
Full-text available
Among the bacterivorous protists, heterotrophic nanoflagellates (HNFs) are considered to be the main grazers of bacteria in freshwaters due to their size-selective grazing. In this work, we assessed the change of a riverine bacterial community in controlled incubations, where HNFs’ predation pressure was initially released through filtration. Filtr...
Article
Full-text available
L’elevata concentrazione di arsenico nelle acque destinate al consumo umano rappresenta un problema di forte interesse pubblico e scientifico su scala globale, considerando l’origine geogenica della contaminazione e i ben documentati effetti negativi sulla salute umana nel lungo termine. Tuttavia, gli aspetti microbiologici legati ai trattamenti di...
Article
Full-text available
Microorganisms play an important role in speciation and mobility of arsenic in the environment, by mediating redox transformations of both inorganic and organic species. Since arsenite [As(III)] is more toxic than arsenate [As(V)] to the biota, the microbial driven processes of As(V) reduction and As(III) oxidation may play a prominent role in medi...
Poster
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The poster shows how ecohydrology acts as an integrative science studying the interaction between hydrology and biota* and using natural processes as management tools to reinforce ecosystem services on a broad range of landscapes (e.g.: coastal, urban and agricultural areas).
Article
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Heterotrophic bacteria play a key role in the degradation of organic matter and carbon cycling in river sediments. These bacterial communities are directly influenced by environmental variables that differ spatially and temporally in rivers. Here, we studied the longitudinal patterns of sediment bacterial community composition and dissolved organic...
Conference Paper
Full-text available
Lake Averno, located in the northwestern part of the active volcanic system of the Phlegrean Fields (Campania, Italy), is hosted in a maar formed during two eruptions occurred 3.7–4.5 ky BP. The lake water shows contributions from a shallow (meteoric) and a deep (hydrothermal) source, the latter having a Na–Cl composition. A pronounced vertical the...
Article
The Chlamydiae are a phylum of obligate intracellular bacteria comprising important human and animal pathogens, yet their occurrence in the environment, their phylogenetic diversity and their host range has been largely underestimated. We investigated the seasonality of environmental chlamydiae in a Tyrrhenian coastal lake. By catalyzed reporter de...