Cannabis sativa L. and Brassica juncea L. grown on arsenic-contaminated industrial soil: potentiality and limitation for phytoremediation.

Phytoremediation represents a natural method to remove contaminants from soil. The goal of this study was to investigate the potential of phosphate-assisted phytoremediation by two energy crops, Cannabis sativa L. and Brassica juncea L.

Interplay between extracellular polymeric substances (EPS) from a marine diatom and model nanoplastic through eco-corona formation.

The occurrence of nanoplastics in oceans' surface waters is no more a hypothesis and it could severely affect marine organisms from different trophic levels. Nanoscale particles interaction with dissolved natural organic matter (NOM) significantly influence their behaviour and consequently bioavailability and toxicity to marine species. Extracellular polymeric substances (EPS) are among the main components of the NOM pool in seawater yet have been so far little investigated for their effect in altering the physical-chemical properties of nanosized objects.

Overcoming limitation of "recalcitrant areas" to phytoextraction process: The synergistic effects of exogenous cytokinins and nitrogen treatments.

The aim of the present work was to test the efficiency of the phytoextraction process involving the use of exogenous phytohormone (cytokinins, CKs) and fertilizer (nitrogen, N) treatments in phytotechnologies to address risk management in "recalcitrant areas". The CKs and N treatments, alone or combined (CKs + N) in a Modulated Application (MA), were tested on the crop plant Helianthus annuus, common to Mediterranean area, fast growing and with high biomass production. Plants were grown on boron (B) contaminated sediments (collected from a geothermal area located in Tuscany (Italy).

Chemical composition of essential oil from plants of abandoned mining site of Elba island.

The essential oil composition of three spontaneous species growing in an abandoned mining of Elba island was analyzed by GC-MS. A total of 194 compounds were identified representing 73.7-100% of the whole oil composition.

TiO nanoparticles in seawater: Aggregation and interactions with the green alga Dunaliella tertiolecta.

Titanium dioxide nanoparticles (TiO NPs) have been widely employed in industrial applications, thus rising concern about their impact in the aquatic environment. In this study we investigated the chemical behaviour of TiO NPs in the culture medium and its effect on the green alga Dunaliella tertiolecta, in terms of growth inhibition, oxidative stress, ROS (Reactive Oxygen Species) accumulation and chlorophyll content. In addition, the influence of exopolymeric substances (EPS) excreted by the microalgae on the stability of NPs has been evaluated.

Response of spontaneous plants from an ex-mining site of Elba island (Tuscany, Italy) to metal(loid) contamination.

The release of large amounts of toxic metals in the neighboring sites of abandoned mine areas represents an important environmental risk for the ecosystem, because it adversely affects soil, water, and plant growth. The aim of the present study was to investigate the metal(loid) (As, Cr, Cu, Ni, Pb, and Zn) contents of native Mediterranean plants grown on the ex-mining area of Elba island (Italy), with the prospective of its recovery by further phytoremediation technology. Soil samples were collected and characterized for metal(loid) content in total and potentially available (EDTA-extractable) fractions.

Toxicological effects of CdSe/ZnS quantum dots on marine planktonic organisms.

Quantum dot nanoparticles (QDs) are proposed as novel materials for photovoltaic technologies, light emitting devices, and biomedical applications. In this study we investigated the effect of CdSe/ZnS QDs on the growth rate of four microalgae: the diatom Phaeodactylum tricornutum, the cryptophyte Rhinomonas reticulata, the prymnesiophyte Isochrysis galbana and the green alga Dunaliella tertiolecta. In addition we analyzed the effect of QDs on the copepod Acartia tonsa.

A SELDI-TOF approach to ecotoxicology: comparative profiling of low molecular weight proteins from a marine diatom exposed to CdSe/ZnS quantum dots.

Quantum dots (QDs), namely semiconductor nanocrystals, due to their particular optical and electronic properties, have growing applications in device technology, biotechnology and biomedical fields. Nevertheless, the possible threat to human health and the environment have attracted increasing attention as the production and applications of QDs increases rapidly while standard evaluation of safety lags. In the present study we performed proteomic analyses, by means of 2D gel electrophoresis and Surface Enhanced Laser Desorption Ionization-Time of Flight-Mass Spectrometry (SELDI-TOF-MS).

The response of Phaeodactylum tricornutum to quantum dot exposure: Acclimation and changes in protein expression.

Nanotechnology has a great potential to improve life and environmental quality, however the fate of nanomaterials in the ecosystems, their bioavailability and potential toxicity on living organisms are still largely unknown, mainly in the marine environment. Genomics and proteomics are powerful tools for understanding molecular mechanisms triggered by nanoparticle exposure. In this work we investigated the effect of exposure to CdSe/ZnS quantum dots (QDs) in the marine diatom Phaeodactylum tricornutum, using different physiological, biochemical and molecular approaches.

Interaction of CdSe/ZnS quantum dots with the marine diatom Phaeodactylum tricornutum and the green alga Dunaliella tertiolecta: a biophysical approach.

In this study, we investigated the interaction of nanoparticles, such as CdSe/ZnS quantum dots (QDs), with the marine diatom Phaeodactylum tricornutum and the green alga Dunaliella tertiolecta, as biological models in the marine environment. Fluorescence kinetics measurements indicated that 30min after dispersion in seawater QDs lost the 60% of the initial emission intensity, possibly due to the occurrence of aggregation processes. However, the presence of algae seemed to mitigate this effect.

Temperature and pressure dependence of azurin stability as monitored by tryptophan fluorescence and phosphorescence. The case of F29A mutant.

The effects of a single-point, F29A, cavity-forming mutation on the unfolding thermodynamic parameters of azurin from Pseudomonas aeruginosa and on the internal dynamics of the protein fold under pressure were probed by the fluorescence and phosphorescence emission of Trp48, deeply buried in the compact hydrophobic core of the macromolecule. Pressure-induced unfolding, monitored by the shift in the fluorescence spectrum, led to a volume change of 70-90mlmol(-1). The difference in the unfolding volume between F29A and wild type azurin was smaller than the volume of the space theoretically created in the mutant, indicating that the cavity is, at least partially, filled with water molecules.

[Susceptibility rate to tigecycline and antibiotic-resistance among Klebsiella pneumoniae strains isolated in Intensive Care Unit].

Antibiotic resistance in Klebsiella pneumoniae strains is an increasing problem in a lot of hospitals. It is a public health emergency because it relates with high mortality rate among patients in Intensive Care Unit (ICU). From 1/1/2009 to 31/08/2010, in ICU of SS Annunziata Hospital of Taranto, 140 isolated Klebsiella pneumoniae strains were detected.

Chemical stability of CdSe quantum dots in seawater and their effects on a marine microalga.

With the increasing use of nanotechnologies, it is expected that nanomaterials end up in natural aquatic systems, from freshwater to the sea. In this work we studied the chemical behaviour of water-soluble CdSe QDs in seawater and their effects on the marine diatom Phaeodactylum tricornutum, as a model of a biological receptor in the marine environment. We evaluated QD toxicity in terms of growth rate inhibition, oxidative stress and ROS accumulation.

Nitrogen fertilizer improves boron phytoextraction by Brassica juncea grown in contaminated sediments and alleviates plant stress.

In this study we evaluated the effect of different fertilizer treatments on Brassica plants grown on boron-contaminated sediments. Experiments were conducted in the laboratory and on the lysimeter scale. At laboratory scale (microcosm), five different fertilizers were tested for a 35-d period.

Changes in the non-protein thiol pool and production of dissolved gaseous mercury in the marine diatom Thalassiosira weissflogii under mercury exposure.

Two detoxification mechanisms working in the marine diatom Thalassiosira weissflogii to cope with mercury toxicity were investigated. Initially, the effect of mercury on the intracellular pool of non-protein thiols was studied in exponentially growing cultures exposed to sub-toxic HgCl(2) concentrations. T.

A phytochelatin-based bioassay in marine diatoms useful for the assessment of bioavailability of heavy metals released by polluted sediments.

The aim of the present work was to develop a new bioassay involving the presence of phytochelatins (PCs), detoxifying intracellular metal-binding peptides, in microalgae as response to metal bioavailability in re-suspensions of metal-polluted marine sediments. For this purpose, the synthesis of PCs has been studied in laboratory cultures of three marine diatoms, namely Phaeodactylum tricornutum, Thalassiosira weissflogii and Skeletonema costatum, exposed to elutriates of sediments collected in a polluted coastal area in the province of Pisa (Tuscany, Italy). Short- and long-term incubations in the elutriates of two marine sediments (named A and B) exhibited an increase of PCs synthesis in all the phytoplanktonic species examined, when the elutriate concentration increased from 0% to 100%.

Phytochelatins in the diatom Phaeodactylum tricornutum Bohlin: an evaluation of their use as biomarkers of metal exposure in marine waters.

The feasibility of a bioassay based on the synthesis of phytochelatins to assess metal pollution in aquatic environments was evaluated by using the marine diatom Phaeodactylum tricornutum. Short-term incubation experiments carried out in EDTA-buffered artificial seawater showed increasing cellular phytochelatin concentration with increasing free cadmium, lead or copper in the medium, indicating that phytochelatins behave as a biomarker of exposure to the bioavailable metal fraction. A linear dose-response relationship between metal exposure and phytochelatin synthesis was found in natural seawater samples enriched with known amounts of heavy metals.

Determination and characterization of phytochelatins by liquid chromatography coupled with on line chemical vapour generation and atomic fluorescence spectrometric detection.

Liquid chromatography (LC) coupled on line with UV/visible diode array detector (DAD) and cold vapour generation atomic fluorescence spectrometry (CVGAFS) has been developed for the speciation, determination and characterization of phytochelatins (PCs). The method is based on a bidimensional approach, e.g.

Biosynthesis of phytochelatins and arsenic accumulation in the marine microalga Phaeodactylum tricornutum in response to arsenate exposure.

The arsenate-induced synthesis of phytochelatins (PC), intracellular cysteine-rich metal-binding peptides, and its relationship with toxicity and with As accumulation in the cell have been studied in laboratory cultures of the marine microalga Phaeodactylum tricornutum. The time course of cellular PC and As in short-term exposures showed that the involvement of PC in the As detoxification as well as the pathway of cellular As depend on the extent of As accumulation and on the rate of PC synthesis. At arsenate concentrations causing As accumulation at a rate exceeding that of PC synthesis, cells seem to activate a mechanism of release of As mainly in a chemical form not complexed with PC.

Biosynthesis of Cd-bound phytochelatins by Phaeodactylum tricornutum and their speciation by size-exclusion chromatography and ion-pair chromatography coupled to ICP-MS.

Cd-bound phytochelatins (Cd-PCs) have been synthesised by incubation of Phaeodactylum tricornutum cell cultures with Cd and purified by size-exclusion chromatography-UV-Vis. These complexes, which were identified in previous work, have now been used as model substances to develop and optimise ion-pair chromatography (IPC) coupled to inductively coupled plasma-mass spectrometry (ICP-MS) for analysis of Cd-PCs. Subsequent analysis of samples taken from Silene vulgaris plants cultivated under heavy metal stress conditions revealed Cd signals but no Cd-PC signals.

Characterization of cadmium- and lead-phytochelatin complexes formed in a marine microalga in response to metal exposure.

Phytochelatins (PCn) are thiol-containing peptides with general structure (gamma-Glu-Cys)n-Gly enzymatically synthesized by plants and algae in response to metal exposure. They are involved in the cellular detoxification mechanism for their capability to form stable metal-phytochelatin complexes. The speciation of Cd and Pb complexes with phytochelatins has been studied in laboratory cultures of the marine diatom Phaeodactylum tricornutum.