Bacteria belonging to the Roseobacter clade of the alpha-Proteobacteria occupy a wide range of environmental niches and are numerically abundant in coastal waters. Here we reveal that Roseobacter-like bacteria may play a previously unrecognized role in the oxidation and cycling of manganese (Mn) in coastal waters. A diverse array of Mn(II)-oxidizing Roseobacter-like species were isolated from E...

Combining scanning tunneling microscopy (STM), IR reflection absorption spectroscopy (IRAS) and molecular beam (MB) techniques, we have investigated particle size effects on a Pd/Fe(3)O(4) model catalyst. We focus on the particle size dependence of (i) CO adsorption, (ii) oxygen adsorption and (iii) Pd nanoparticle oxidation/reduction. The model system, which is based on Pd nanoparticles suppor...

A polypyrrole (PPy) composite film with a pure PPy zone and a PPy–TiO2 nanoparticle composite zone in its cross-sectional direction was synthesized by direct oxidation of pyrrole successively in an electrolyte with or without TiO2 nanoparticles. The volume content of TiO2 in the composite film was tested to be lower than 0.9%. The actuator fabricated from this monolithic PPy film bends uniforml...

Samples from six depths of the Black Sea's suboxic zone were analyzed for 16S rRNA gene sequence information. A gradient in phylotype diversity was found. The distributions of known anaerobic ammonium oxidation (anammox) bacteria, many unknown Planctomycetes, and other phylotypes were examined in relation to the local nutrient and redox conditions.

The effect of in situ chemical oxidation (ISCO) with permanganate (MnO4-) on tetrachloroethene (PCE) in a dual permeability system consisting of low permeability clay with high permeability sand lenses was investigated by two-dimensional laboratory experiments. The experiments imitate a field remediation at a former dry cleaning facility in Denmark. Results from laboratory experiments and field...

The design, characterization, and performance of a bioreactor-settler system that allows the partial biological oxidation of reduced sulfur compounds is described. The design incorporates the physical separation of the aeration from the bioreactor. The reactor has a dynamic flow zone and a static zone. Steady state thiosulfate-oxidizing cultures were established at different O2/S2O32− molar rat...

Oxygen minimum zones (OMZ) are areas in the global ocean where oxygen concentrations drop to below one percent. Low oxygen concentrations allow alternative respiration with nitrate and nitrite as electron acceptor to become prevalent in these areas, making them main contributors to oceanic nitrogen loss. The contribution of anammox and denitrification to nitrogen loss seems to vary in different...