Publications by authors named "Francesco Valentino"

Most stars in today's Universe reside within spheroids, which are bulges of spiral galaxies and elliptical galaxies. Their formation is still an unsolved problem. Infrared/submillimetre-bright galaxies at high redshifts have long been suspected to be related to spheroid formation.

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Gas-permeable membrane (GPM) technology is gaining interest to recover nitrogen from residual effluents due to its effectiveness, simple operation and capacity of producing a nutrient rich product with fertilising value. In this study, a GPM contactor was used at 25 °C to recover total ammoniacal nitrogen (TAN) from swine slurry as a concentrated (NH)SO solution. Firstly, a synthetic solution was tested on a wide pH range (6-12).

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Tannery sludge, a challenging waste, was utilized as a substrate for the production of Short-Chain Fatty Acids (SCFAs) through a series of six thermophilic Continuous Stirred-Tank Reactor runs. The sludge was subjected to a mild thermal pre-treatment and incorporated zeolites (chabazite in run II, and clinoptilolite in run III) in the acidification process. Results highlighted zeolites' impact on chromium concentration and the SCFAs/COD ratio.

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The present study describes the microbial production of polyhydroxyalkanoates (PHA) from thermally pre-treated sewage sludge at pilot scale level, investigating for the first time the effect of the organic loading rate (OLR) under oxygen limitation on biomass storage properties and kinetics. Polymer characteristics have been also evaluated. The selection/enrichment of PHA-storing biomass was successfully achieved in a Sequencing Batch Reactor (SBR) under short hydraulic retention time (HRT; 2 days).

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Dairy products, extra virgin olive oil, red and white wines are excellent food products, appreciated all around the world. Their productions generate large amounts of by-products which urge for recycling and valorization. Moreover, another abundant waste stream produced in urban context is the Organic Fraction of Municipal Solid Wastes (OFMSW), whose global annual capita production is estimated at 85 kg.

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Volatile fatty acid (VFA) rich streams from fermentation of organic residuals and wastewater are suitable feedstocks for mixed microbial culture (MMC) Polyhydroxyalkanoate (PHA) production. However, many such streams have low total VFA concentration (1-10 gCOD/L). PHA accumulation requires a flow-through bioprocess if the VFAs are not concentrated.

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Over the last years, in a search for sustainable and biodegradable alternatives to petrol-based plastics, biotechnological applications turned to the potentialities of mixed microbial cultures (MMC) for producing polyhydroxyalkanoates (PHAs). Under a feast and famine regime, an uncoupled carbon (C) and nitrogen (N)-feeding strategy may be adopted by dosing the C-source at the beginning of the feast and the N-source at the beginning of the famine in order to stimulate a PHA storage response and microbial growth. Even though this strategy has been already successfully applied for the PHA production, very few information is to date available regarding the MMC operating in these systems and the influence of Organic Loading Rate (OLR) on their selection and enrichment.

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Star formation in half of massive galaxies was quenched by the time the Universe was 3 billion years old. Very low amounts of molecular gas seem to be responsible for this, at least in some cases, although morphological gas stabilization, shock heating or activity associated with accretion onto a central supermassive black hole are invoked in other cases. Recent studies of quenching by gas depletion have been based on upper limits that are insufficiently sensitive to determine this robustly, or stacked emission with its problems of averaging.

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Volatile fatty acids obtained from the fermentation of the organic fraction of municipal solid waste can be used as raw materials for non-toxic ethyl ester (EE) synthesis as well as feedstock for the production of polyhydroxyalkanoates (PHAs). Taking advantage of the concept of an integrated process of a bio-refinery, in the present paper, a systematic investigation on the extraction of intracellular poly(3-hydroxybutyrate--3-hydroxyvalerate), produced by mixed microbial culture by using EEs was reported. Among the tested EEs, ethyl acetate (EA) was the best solvent, dissolving the copolymer at the lowest temperature.

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Polyhydroxyalkanoates (PHAs) production at pilot scale has been recently investigated and carried out exploiting different process configurations and organic wastes. More in detail, three pilot platforms, in Treviso (North-East of Italy), Carbonera (North-East of Italy) and Lisbon, produced PHAs by open mixed microbial cultures (MMCs) and different organic waste streams: organic fraction of municipal solid waste and sewage sludge (OFMSW-WAS), cellulosic primary sludge (CPS), and fruit waste (FW), respectively. In this context, two stabilization methods have been applied, and compared, for preserving the amount of PHA inside the cells: thermal drying and wet acidification of the biomass at the end of PHA accumulation process.

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Polyhydroxyalkanoates (PHAs) are well-known biodegradable plastics produced by various bacterial strains, whose major drawback is constituted by the high cost of their synthesis. Producing PHAs from mixed microbial cultures and employing organic wastes as a carbon source allows us to both reduce cost and valorize available renewable resources, such as food waste and sewage sludge. However, different types of pollutants, originally contained in organic matrices, could persist into the final product, thus compromising their safety.

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The present study reports on the production and characterization of a new biopackaging material made of poly(3-hydroxybutyrate--3-hydroxyvalerate) (PHBV) derived from municipal biowaste (MBW) and produced by the mixed bacterial culture technology. After purification and extraction, the MBW-derived PHBV was processed by electrospinning to yield defect-free ultrathin fibers, which were thermally post-treated. Annealing at 130 °C, well below the biopolymer's melting temperature (), successfully yielded a continuous film resulting from coalescence of the electrospun fibrillar morphology, the so-called biopaper, exhibiting enhanced optical and color properties compared to traditional melt compounding routes.

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The utilisation of urban organic waste as feedstock for polyhydroxyalkanoates (PHA) production is growing since it allows to solve the main concerns about their disposal and simultaneously to recover added-value products. A pilot scale platform has been designed for this purpose. The VFA-rich fermentation liquid coming from the anaerobic treatment of both source-sorted organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS) has been used as substrate for the aerobic process steps: a first sequencing batch reactor (SBR, 100 L) for the selection of a PHA-producing biomass, and a second fed-batch reactor (70 L) for PHA accumulation inside the cells.

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In line with the Circular Economy approach, the production of polyhydroxyalkanoate (PHA) with organic waste as the feedstock may a biotechnological application to reduce waste and recover high-value materials. The potential contaminants that could transfer from bio-waste to a PHA include inorganic elements, such as heavy metals. Hence, the total content and migratability of certain elements were evaluated in several PHA samples produced from different origins and following different methods.

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The microbial synthesis of polyhydroxyalkanoates (PHA) from organic wastes is a valuable process to valorize available renewable resources, such as food wastes and biological sludge. Bioplastics find many applications in various sectors, from medical field to food industry. However, persistent organic pollutants could be transferred from wastes to the final product.

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The selection and enrichment of a mixed microbial culture (MMC) for polyhydroxyalkanoates (PHA) production is a well-known technology, typically carried out in sequencing batch reactors (SBR) operated under a feast-famine regime. With a nitrogen-deficient carbon source to be used as feedstock for PHA synthesis, a nutrient supply in the SBR is required for efficient microbial growth. In this study, an uncoupled carbon (C) and nitrogen (N) feeding strategy was adopted by dosing the C-source at the beginning of the feast and the N-source at the beginning of the famine, at a fixed C/N ratio of 33.

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This study focuses on the application of the concept of circular economy, with the creation of added-value marketable products and energy from organic waste while minimizing environmental impacts. Within this purpose, an urban biorefinery technology chain has been developed at pilot scale in the territorial context of the Treviso municipality (northeast Italy) for the production of biopolymers (polyhydroxyalkanoates, PHAs) and biogas from waste of urban origin. The piloting system (100-380 L) comprised the following units: a) acidogenic fermentation of the organic fraction of municipal solid waste (OFMSW) and biological sludge; b) two solid/liquid separation steps consisting of a coaxial centrifuge and a tubular membrane (0.

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This study analyses the bacterial population dynamics of a mixed microbial community (MMC) selected in a pilot plant producing polyhydroxyalkanoate (PHA) from the fermentation of the organic fraction of urban waste (OFMSW) and sewage sludge (SS). 16S rRNA gene high-throughput sequencing revealed the occurrence of a variety of PHA accumulating bacteria that ensured a stable PHA production in an open system operating with real substrates and without temperature control. The Volatile Fatty Acids (VFA) changes in the feed and the temperature variation affected the dynamics of the PHA-accumulating bacteria over the plant operation.

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The problem of waste disposal has recently focused on practices for waste recycling and bio-resources valorization. Organic waste produced in urban context together with biological sludge produced in wastewater treatment plants (WWTPs) can be used as renewable feedstock for the production of building blocks of different products, from biopolymers to methyl esters. This paper deals with the optimization of the fermentation process in order to transform urban organic waste (a mixture of pre-treated food waste and biological sludge) into added-value volatile fatty acid (VFA) rich stream, useful for biological processes within a biorefinery technology chain.

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Among the organic contaminants that could pass from waste to polyhydroxyalkanoates (PHAs), there are the polycyclic aromatic hydrocarbons (PAHs). For this reason, we have developed a rapid analytical method for the determination of sixteen PAHs in PHAs. PAHs were extracted by n-hexane, after matrix dispersion and crumbling into sand; the extract was purified by solid phase extraction using florisil as adsorbent.

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New therapeutic options in non-small-cell lung cancer have been available through a great in-depth and genomic research, improving preclinical disease patterns and identifying the specific toxicity of target therapy. The multidisciplinary approach, increasingly practiced among clinicians, researchers, pharmaceutical companies and ethics committees has allowed the emergence of a new generation of translational clinical trials and the adoption of new technologies (e.g.

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A pure culture of the filamentous bacterium Thiothrix, strain CT3, was aerobically cultured in a chemostat under continuous acetate feeding at three different culture residence times (RT 6, 12 or 22 d) and the same volumetric organic load rate (OLR 0.12gCOD/L/d). Cells cultured at decreasing RT in the chemostat had an increasing transient response to acetate spikes in batch tests.

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A sequencing batch reactor (SBR) is typically used for selecting mixed microbial cultures (MMC) for polyhydroxyalkanoate (PHA) production. Since many waste streams suitable as process feedstock for PHA production are nitrogen-deficient, a nutrient supply in the SBR is typically required to allow for efficient microbial growth. The scope of this study was to devise a nitrogen feeding strategy which allows controlling the nitrogen levels during the feast and famine regime of a lab-scale SBR, thereby selecting for PHA-storing microorganisms.

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Polyhydroxyalkanoates (PHA) are biodegradable polyesters that can be produced in bioprocesses from renewable resources in contrast to fossil-based bio-recalcitrant polymers. Research efforts have been directed towards establishing technical feasibility in the use of mixed microbial cultures (MMC) for PHA production using residuals as feedstock, mainly consisting of industrial process effluent waters and wastewaters. In this context, PHA production can be integrated with waste and wastewater biological treatment, with concurrent benefits of resource recovery and sludge minimization.

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