Haloarchaea as Promising Chassis to Green Chemistry.

Climate change and the scarcity of primary resources are driving the development of new, more renewable and environmentally friendly industrial processes. As part of this green chemistry approach, extremozymes (extreme microbial enzymes) can be used to replace all or part of the chemical synthesis stages of traditional industrial processes. At present, the production of these enzymes is limited by the cellular chassis available.

Monitoring of abiotic degradation of photocrosslinked silicone acrylate coatings: the fate of the photoinitiator.

Photocrosslinked silicone acrylates are used in a variety of applications, such as printing inks, adhesives, or adhesive release liners. Their production requires the use of a photoinitiator. Even if the photoinitiator represents a minor mass in the photocurable formulation (2-10%), it is used in excess and residual amounts may therefore remain in the polymerized products and possibly migrate into the environment during the use of the products and/or at their end-of-life stage.

"NiCo Buster": engineering E. coli for fast and efficient capture of cobalt and nickel.

Background: Metal contamination is widespread and results from natural geogenic and constantly increasing anthropogenic sources (mainly mining and extraction activities, electroplating, battery and steel manufacturing or metal finishing). Consequently, there is a growing need for methods to detoxify polluted ecosystems. Industrial wastewater, surface water and ground water need to be decontaminated to alleviate the contamination of soils and sediments and, ultimately, the human food chain.

Implications of effluent organic matter and its hydrophilic fraction on zinc(II) complexation in rivers under strong urban pressure: aromaticity as an inaccurate indicator of DOM-metal binding.

The zinc binding characteristics of dissolved organic matter (DOM) fractions from the Seine River Basin were studied after being separated and extracted according to their polarity: hydrophobic, transphilic, and hydrophilic. The applied experimental methodology was based on a determination of labile zinc species by means of differential pulse anodic stripping voltammetry (DPASV) at increasing concentrations of total zinc on a logarithmic scale and at fixed levels of: pH, ionic strength, and temperature. Fitting the DOM fractions with two discrete classes of ligands successfully allowed determining the conditional zinc binding constants (Ki) as well as total ligand density (LiT).

An adaptable automatic trace metal monitoring system for on line measuring in natural waters.

An adaptable automatic trace metal monitoring system (ATMS) was assembled and embedded in a mobile monitoring station belonging to the French Water Agency Artois-Picardie (AEAP) and deployed in the field to measure the concentration of trace metals (electroactive and acid leachable fractions) in natural waters by anodic stripping voltammetry with a hanging mercury drop electrode. Cathodic stripping voltammetry procedures were included to estimate the concentration of dissolved oxygen and reduced sulphur species. The concept of the measuring system enables easy adaptation of methods and procedures to analytes of concern and gives the opportunity to undertake in real-time a routine analysis of the dynamic behaviour of trace metals in river, pond and seawater.

On the lability of dissolved Cu, Pb and Zn in freshwater: optimization and application to the Deûle (France).

A procedure to determine lead and zinc by anodic stripping voltammetry and copper by cathodic stripping voltammetry in natural river samples was developed and validated. Cu determination involves the adsorption of Cu complexes with 8-hydroxyquinoline (oxine) onto a hanging mercury drop electrode. All samples were studied at natural pH and following optimal conditions were found: an accumulation step at -1.

Significance of data treatment and experimental setup on the determination of copper complexing parameters by anodic stripping voltammetry.

Different procedures of voltammetric peak intensities determination, as well as various experimental setups were systematically tested on simulated and real experimental data in order to identify critical points in the determination of copper complexation parameters (ligand concentration and conditional stability constant) by anodic stripping voltammetry (ASV). Varieties of titration data sets (Cu(measured)vs. Cu(total)) were fitted by models encompassing discrete sites distribution of one-class and two-class of binding ligands (by PROSECE software).

Characterisation and modelling of marine dissolved organic matter interactions with major and trace cations.

A two-step protocol (nano-filtration and reverse osmosis) was applied for natural organic matter (NOM) preconcentration of a seawater sample. Complexing affinities of the so concentrated marine dissolved NOM (DNOM) towards major and trace cations were studied by potentiometric and voltammetric titration techniques. The potentiometric titration experiments fitted by models describing and characterising the DNOM-cation interactions, revealed four distinct classes of acidic sites (pKa of 3.

Study of interactions of concentrated marine dissolved organic matter with copper and zinc by pseudopolarography.

The interaction of dissolved organic matter (DOM) with copper and zinc in a concentrated seawater sample was characterised by pseudopolarography. Measurements performed at increased concentrations of copper(II) ions showed successive saturation of active DOM sites which indicate possible partition of copper between (i) free or labile complexes, (ii) reduced and released within the potential window of the method, and (iii) electroinactive copper complexes. Pseudopolarograms measured at pH 4 indicate a release of copper which was bound to the active sites of DOM that formed non-labile complexes.

Speciation of trace metals in natural waters: the influence of an adsorbed layer of natural organic matter (NOM) on voltammetric behaviour of copper.

The influence of an adsorbed layer of the natural organic matter (NOM) on voltammetric behaviour of copper on a mercury drop electrode in natural water samples was studied. The adsorption of NOM strongly affects the differential pulse anodic stripping voltammogram (DPASV) of copper, leading to its distortion. Phase sensitive ac voltammetry confirmed that desorption of adsorbed NOM occurs in general at accumulation potentials more negative than -1.