Assessment of Full-Scale NO Emission Characteristics and Testing of Control Concepts in an Activated Sludge Wastewater Treatment Plant with Alternating Aerobic and Anoxic Phases.

This work aims to obtain full-scale NO emission characteristics translatable into viable NO control strategies and conduct full-scale testing of the proposed NO control concepts. Data of a long-term monitoring campaign was first used to quantify full-scale NO emission and probe into the seasonal pattern. Then trends between NO production/emission and process variables/conditions during typical operating cycles were revealed to explore the dynamic NO emission behavior.

Anaerobic Methanotrophic Archaea of the ANME-2d Cluster Are Active in a Low-sulfate, Iron-rich Freshwater Sediment.

ANaerobic MEthanotrophic (ANME) archaea remove the greenhouse gas methane from anoxic environments and diminish its flux to the atmosphere. High methane removal efficiencies are well documented in marine environments, whereas anaerobic oxidation of methane (AOM) was only recently indicated as an important methane sink in freshwater systems. Freshwater AOM-mediating microorganisms lack taxonomic identification and only little is known about metabolic adaptions to prevailing biogeochemical conditions.

Quantitative proteomics of Chlorobaculum tepidum: insights into the sulfur metabolism of a phototrophic green sulfur bacterium.

Chlorobaculum (Cba.) tepidum is a green sulfur bacterium that oxidizes sulfide, elemental sulfur, and thiosulfate for photosynthetic growth. To gain insight into the sulfur metabolism, the proteome of Cba.

Comparative proteomics and activity of a green sulfur bacterium through the water column of Lake Cadagno, Switzerland.

Primary production in the meromictic Lake Cadagno, Switzerland, is dominated by anoxygenic photosynthesis. The green sulfur bacterium Chlorobium clathratiforme is the dominant phototrophic organism in the lake, comprising more than half of the bacterial population, and its biomass increases 3.8-fold over the summer.

Dominance of a clonal green sulfur bacterial population in a stratified lake.

For many years, the chemocline of the meromictic Lake Cadagno, Switzerland, was dominated by purple sulfur bacteria. However, following a major community shift in recent years, green sulfur bacteria (GSB) have come to dominate. We investigated this community by performing microbial diversity surveys using FISH cell counting and population multilocus sequence typing [clone library sequence analysis of the small subunit (SSU) rRNA locus and two loci involved in photosynthesis in GSB: fmoA and csmCA].

Temperature effect on the sulfur isotope fractionation during sulfate reduction by two strains of the hyperthermophilic Archaeoglobus fulgidus.

Sulfur isotope fractionation during dissimilatory sulfate reduction by two strains of the thermophilic archaeon Archaeoglobus fulgidus (strains VC-16 and Z) was explored over the entire temperature range of growth. The optimal cell-specific sulfate reduction rate (14 fmol cell(-1) h(-1)) was found at 82-84 degrees C but growth was measured as low as 54 degrees C. The fractionation ranged between 0.

High rates of sulfate reduction in a low-sulfate hot spring microbial mat are driven by a low level of diversity of sulfate-respiring microorganisms.

The importance of sulfate respiration in the microbial mat found in the low-sulfate thermal outflow of Mushroom Spring in Yellowstone National Park was evaluated using a combination of molecular, microelectrode, and radiotracer studies. Despite very low sulfate concentrations, this mat community was shown to sustain a highly active sulfur cycle. The highest rates of sulfate respiration were measured close to the surface of the mat late in the day when photosynthetic oxygen production ceased and were associated with a Thermodesulfovibrio-like population.

Effect of low sulfate concentrations on lactate oxidation and isotope fractionation during sulfate reduction by Archaeoglobus fulgidus strain Z.

The effect of low substrate concentrations on the metabolic pathway and sulfur isotope fractionation during sulfate reduction was investigated for Archaeoglobus fulgidus strain Z. This archaeon was grown in a chemostat with sulfate concentrations between 0.3 mM and 14 mM at 80 degrees C and with lactate as the limiting substrate.

Calibration of sulfate levels in the archean ocean.

The size of the marine sulfate reservoir has grown through Earth's history, reflecting the accumulation of oxygen into the atmosphere. Sulfur isotope fractionation experiments on marine and freshwater sulfate reducers, together with the isotope record, imply that oceanic Archean sulfate concentrations were <200 microM, which is less than one-hundredth of present marine sulfate levels and one-fifth of what was previously thought. Such low sulfate concentrations were maintained by volcanic outgassing of SO2 gas, and severely suppressed sulfate reduction rates allowed for a carbon cycle dominated by methanogenesis.