Percorrer por autor "Piccirillo, Clara"
A mostrar 1 - 10 de 33
Resultados por página
Opções de ordenação
- Bacteria immobilsation on hydroxyapatite surface for wastewater treatmentPublication . Pereira, Sofia Isabel Almeida; Piccirillo, Clara; Marques, Ana P. G. C.; Pullar, Robbert C.; Pintado, Manuela M. E.; Castro, Paula M. L.Heavy metals pollution in the environment is a big cause of concern, due to the toxicity of the metals themselves. In this work we propose an innovative method for heavy metals removal from contaminated waste water – a combination of hydroxyapatite (already used for water treatment) and microorganisms. Selected bacterial strains were immobilised on the surface of hydroxyapatite of natural origin (extracted from cod fish bones). These systems were used to tested on heavy metals, such as zinc and cadmium, from water solutions. The three strains used were Pseudomonas fluorescens, Microbacterium oxydans and Cupravidus sp.; they were selected as they showed high heavy metal resistance. SEM micrographies were used to study their immobilization on the hydroxyapatite surface. Solutions containing different concentrations of either Zn (II), Cd (II) or both metals at the same time were used. Results showed that the combination of hydroxyapatite and bacteria increases the metal uptake, indicating a synergistic action between the solid support and the bacteria biofilm. Particularly high removal rates were observed for higher heavy metal concentrations and for the Pseudomonas fluorescens strain. This work shows a promising way for environmental remediation, combining products of natural origin with microbiology.
- Biodegradation of carbamazepine by the bacterial strain labrys portucalensis F11Publication . Bessa, V. S.; Moreira, I. S.; Murgolo, Sapia; Piccirillo, Clara; Mascolo, Giuseppe; Castro, P. M. L.Introduction and Objectives: The occurrence of pharmaceuticals in the environment is a topic of concern. Most pharmaceuticals are not completely mineralized in the human body and are released to the sewage systems as the pharmaceutical itself and as their “biologically active” metabolites Wastewater treatment plants (WWTPs) are not designed to remove them and they are released into the environment. Despite generally found at low concentrations (ranging from ngL−1 to μgL−1), they are classified as persistent microcontaminants due to their continuous release. Carbamazepine (CBZ) is a widely used anticonvulsant which has been found in different environmental compartments and has been suggested as a molecular marker of contamination in surface water and groundwater. In the present study, biodegradation of CBZ by strain Labrys Portucaliensis F11 was assessed. Transformation products (TPs) resulting from CBZ degradation were analysed. Methodology: CBZ biodegradation assays were performed in minimal salts medium (MM) supplemented with 2.0, 4.0, 10.0, 20.0 and 40.0 𝜇M of CBZ as a sole carbon and energy source and in the presence of acetate (5.9mM); CBZ was quantified by High Performance Liquid Chromatography (HPLC); Transformation products (TPs) were detected and identified by UPLCQTOF/MS/MS; Ecotoxicological effects of cultures containing CBZ and of cultures containing the TPs after microbial degradation were assessed using Daphnia magna (OCED Guideline 202) and Lepidium sativum (OECD Guideline 208). Highlights: Supplementation with a second carbon source had a positive effect on CBZ degradation by strain Labrys Portucalensis F11; CBZ degradation by strain F11 proceeds mainly by oxidation, hydroxilation, hydrolysis and cleavage of the aromatic ring; CBZ TPs were detected until the end of the experiment time; CBZ and transformation products exhibited high toxicity on D. magna whereas inhibition of root elongation of L. sativum was practically neglectable.
- Biodegradation of carbamazepine by the bacterial strain labrys portucalensis F11 : metabolism and toxicologic studiesPublication . Bessa, Vânia S.; Moreira, Irina; Murgulo, Sapia; Piccirillo, Clara; Mascolo, Giuseppe; Castro, Paula M. L.Background: Occurrence of pharmaceuticals in the environment is a topic of concern. Most pharmaceuticals are not completely mineralized and are released on the sewage systems through excretion and by improper elimination and disposal. Municipal wastewater treatment plants (WWTPs) are not designed to remove them and they are released into the environment. They are classified as persistent microcontaminants due to their continuous release even if at low concentrations. Carbamazepine (CBZ) is an widely used anticonvulsant and has been suggested as a molecular marker of contamination in surface water and groundwater. Method Biodegradation of CBZ by the bacterial strain Labrys portucalensis F11 was tested as sole carbon and energy source (0.04 mM) and in the presence of acetate as primary carbon source. Transformation products (TPs) were detected and identified by UPLCQTOF/MS/MS. Ecotoxicologiacl effects of CBZ and the TPs resultant from biodegradation were evaluated at different trophic levels, i) zooplanckton (Dapnhia magna) and ii) plants (Lipidium sativum). The 24–48 h immobilization of D. magna bioassays were performed following the Standard Operational Procedures of Daphtoxkit FTM. The toxicity was measured as the immobilization of D. magna according to the procedures OCED Guideline 202. The bioassay with L. sativum evaluated the potential toxicity considering the root elongation according to OECD Guideline 208. Results & Conclusions Strain F11 was able to degrade 95% of initial CBZ concentration during 30 days experiment. Supplementation with acetate increased degradation to 100% in 24 days. A group of 12 TPs formed in the microbial process were identified; CBZ degradation by strain F11 proceeds mainly by oxidation, hydroxilation and cleavage of the aromatic ring. The effect of whole biodegradation products on root elongation of L. sativum was practically neglectable; however the same exhibited toxicity to D. magna. Strain Labrys portucalensis F11 proved to be able to degrade CBZ and may be potentially useful for biotechnological applications.
- Biodegradation of diclofenac by the bacterial strain labrys portucalensis Fl 1Publication . Moreira, Irina S.; Bessa, Vânia S.; Murgolo, Sapia; Piccirillo, Clara; Mascolo, Giuseppe; Castro, Paula M.L.Diclofenac (DCF) is a widely used non-steroidal anti-inflammatory pharmaceutical which is detected in the environment at concentrations which can pose a threat to living organisms. In this study, biodegradation of DCF was assessed using the bacterial strain Labrys portucalensis F11. Biotransformation of 70% of DCF (1.7–34 μM), supplied as the sole carbon source, was achieved in 30 days. Complete degradation was reached via co-metabolism with acetate, over a period of 6 days for 1.7 µM and 25 days for 34 μM of DCF. The detection and identification of biodegradation intermediates was performed by UPLC-QTOF/MS/MS. The chemical structure of 12 metabolites is proposed. DCF degradation by strain F11 proceeds mainly by hydroxylation reactions; the formation of benzoquinone imine species seems to be a central step in the degradation pathway. Moreover, this is the first report that identified conjugated metabolites, resulting from sulfation reactions of DCF by bacteria. Stoichiometric liberation of chlorine and no detection of metabolites at the end of the experiments are strong indications of complete degradation of DCF by strain F11. To the best of our knowledge this is the first report that points to complete degradation of DCF by a single bacterial strain isolated from the environment.
- Calcium phosphate-based materials of natural origin showing photocatalytic activityPublication . Piccirillo, Clara; Dunnill, Charles W.; Pullar, Robert C.; Tobaldi, David M.; Labrincha, João A.; Parkin, Ivan P.; Pintado, Manuela M.; Castro, Paula M. L.Calcium phosphate based materials of natural origin with photocatalytic properties were produced. Bones of Atlantic cod fish were treated in appropriate solutions (either Ca- or Ti-containing salts) and successively annealed. Results showed multiphasic materials (hydroxyapatite, beta-tricalcium phosphate and anatase titania) with excellent photocatalytic performance under both UV and visible light, with an anatase concentration of only about 2 mol%. Results with such a low amount of anatase have never been reported before for a calcium phosphate-based material; this is attributed to the presence of anatase being mainly on the surface. Single-phase hydroxyapatite (Ca-10(PO4)(6)(OH)(2) or HAp) also showed some photocatalytic properties and antibacterial activity.
- Cassava (manihot esculenta crantz) and yam (dioscorea spp.) crops and their derived foodstuffs: safety, security and nutritional valuePublication . Ferraro, Vincenza; Piccirillo, Clara; Tomlins, Keith; Pintado, M. E.Cassava (Manihot esculenta Crantz) and yam (Dioscorea spp.) are tropical crops consumed by ca. 2 billion people and represent the main source of carbohydrate and energy for the approximately 700million people living in the tropical and sub-tropical areas. They are a guarantee of food security for developing countries. The production of these crops and the transformation into food-derived commodities is increasing, it represents a profitable business and farmers generate substantial income from their market. However, there are some important concerns related to the food safety and food security. The high post-harvest losses, mainly for yam, the contamination by endogenous toxic compounds, mainly for cassava, and the contamination by external agents (such as micotoxins, pesticides, and heavy metal) represent a depletion of economic value and income. The loss in the raw crops or the impossibility to market the derived foodstuffs, due to incompliance with food regulations, can seriously limit all yam tubers and the cassava roots processors, from farmers to household, from small-medium to large enterprises. One of the greatest challenges to overcome those concerns is the transformation of traditional or indigenous processing methods into modern industrial operations, from the crop storage to the adequate package of each derived foodstuff.
- Characterization and antimicrobial properties of food packaging methylcellulose films containing stem extract of Ginja cherryPublication . Campos, Débora; Piccirillo, Clara; Pullar, Robert C; Castro, Paula ML; Pintado, Maria MEBACKGROUND: Food contamination and spoilage is a problem causing growing concern. To avoid it, the use of food packaging with appropriate characteristics is essential; ideally, the packaging should protect food from external contamination and exhibit antibacterial properties. With this aim, methylcellulose (MC) films containing natural extracts from the stems of Ginja cherry, an agricultural by-product, were developed and characterized. RESULTS: The antibacterial activity of filmswas screened by the disc diffusion method and quantified using the viable cell count assay. The films inhibited the growth of both Gram-positive and Gram-negative strains (Listeria innocua, methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus, Salmonella Enteritidis, Escherichia coli). For the films with lower extract content, effectiveness against the microorganisms depended on the inoculum concentration. Scanning electron microscope images of the films showed that those containing the extracts had a smooth and continuous structure. UV–visible spectroscopy showed that thesematerials do not transmit light in the UV. CONCLUSION: This study shows that MC films containing agricultural by-products, in this case Ginja cherry stem extract, could be used to prevent food contamination by relevant bacterial strains and degradation by UV light. Using such materials in food packaging, the shelf life of food products could be extended while utilizing an otherwise wasted by-product.
- Chitosan and codfish hydroxyapatite formulation to be used as coating material to circumvent periprosthetic joint infectionsPublication . Costa-Pinto, Ana R.; Lemos, Ana L.; Piccirillo, Clara; Tavaria, Freni K; Pintado, Manuela E.
- Exploring the fate of chiral pharmaceuticals in an AGS system under saltwater intrusion phenomenaPublication . Miranda, Catarina; Amorim, Catarina; Piccirillo, Clara; Tiritan, Maria Elizabeth; Castro, PaulaAerobic granular sludge (AGS) is a robust technology, largely adopted in wastewater treatment plants (WWTPs) worldwide. However, there is a lack of knowledge regarding how this technology deals with saltwater intrusion and variable daily wastewater salinity loads. With the sea level rise, in coastline WWTPs, seawater infiltration into sewers is a growing problem. In addition, the increase in pharmaceutical production and consumption led to their accumulation in wastewater. Many of these are chiral pharmaceuticals (CPs) whose enantiomers can differ in their degradation ratio and toxicity in the environment. The fate of CPs in AGS systems is scarcely reported, especially if combined with variable salt concentration in wastewater. In this study, an AGS reactor was operated for 132 days for the treatment of urban saline wastewater sporadically containing a mixture of CPs namely: tramadol and venlafaxine and its metabolites o-desmethyltramadol and o-desmetylvenlafaxine, respectively, at concentrations near those found in the environment (8 μg/L). Both daily salinity fluctuations and the presence of CPs in wastewater did not affect the biological removal of COD, N, and P. However, the AGS system was not able to remove the CPs that ended up in the effluent. To address this challenge, a parallel experiment was performed using a bone char material derived from fish-food waste (tuna bones) to adsorb the pharmaceuticals tramadol and venlafaxine. The bone char exhibited removal efficiencies of around 40%, as such in combination with AGS systems it can help to decrease the release of CPs into the environment.
- Exploring the potential of a waste-derived bone char for pharmaceuticals adsorption in saline-based wastewaterPublication . Miranda, Catarina; Scalera, Francesca; Piancastelli, Andreana; Pullar, Robert C.; Tiritan, Maria Elizabeth; Piccirillo, Clara; Castro, Paula M. L.; Amorim, Catarina L.In this study, the effect of salinity in wastewater on the adsorption capacity of a bone char material prepared through pyrolysis of tuna bones at 1000 °C was investigated for two pharmaceuticals, tramadol (TRA) and venlafaxine (VNF), both contaminants of emerging concern. This is the first time that the adsorption efficiency of a bone char-type material was tested in such conditions. The Tuna Bone Char (TBC) was composed of calcium phosphate (hydroxyapatite), and graphitic carbon. The TBC is a nanostructured material (particle size 30–60 nm), with a surface area of 100.67 m2/g (higher than other waste-derived type materials), and a total pore volume of 575.2 mm3/g. TBC capacity to adsorb TRA and VNF, individually or combined, was evaluated in batch experiments using different aqueous matrices: water, non-saline wastewater, and wastewaters with different salinity levels (7.5 and 12 g/L). For individual pharmaceuticals, the TBC had a higher affinity for TRA than VNF. The presence of salts in wastewaters led to a decrease in the TBC adsorption capacity but it was still effective for pharmaceuticals adsorption. Indeed, for the individual pharmaceuticals, the TBC adsorption capacity (qt) was 0.72–2.14 and 0.77–1.70 mg/g for TRA and VNF respectively, depending on the aqueous matrix. With both pharmaceuticals present, lower qt values were experimentally obtained for TRA and VNF. The potential of the TBC, a material derived from a by-product of the fish industry, to be used for environmental remediation in different environments, such as saline wastewaters was demonstrated, widening the range of its potential applications.