The bifunctional CO dehydrogenase/acetyl-CoA synthase (CODH/ACS) plays a central role in the Wood-Ljungdahl pathway of autotrophic CO(2) fixation. A recent structure of the Moorella thermoacetica enzyme revealed that the ACS active site contains a [4Fe-4S] cluster bridged to a binuclear Cu-Ni site. Here, biochemical and x-ray absorption spectroscopic (XAS) evidence is presented that the copper ...

2-Bromoethanesulfonate (BES) inhibited the reductive dechlorination of chloroethenes in several sediment-free enrichment cultures in the absence of methanogenic archaea. Archaeon-specific PCR primers confirmed the absence of methanogens in the enrichment cultures. BES should not be used to attribute dechlorination activities to methanogens.

The effect of zero-valent iron nanoparticles (nZVI) addition on methane production during anaerobic digestion pig slurry was assessed. Experiments were conducted using two experimental set-ups: batch and long-term continuous operation at a fixed nZVI dosage. Two different temperature ranges (mesophilic thermophilic) Biogas content monitored, the specific methanogenic activity biomass oxidation ...

A culture-independent molecular phylogenetic approach was used to survey constituents of microbial communities associated with an aquifer contaminated with hydrocarbons (mainly jet fuel) and chlorinated solvents undergoing intrinsic bioremediation. Samples were obtained from three redox zones: methanogenic, methanogenic-sulfate reducing, and iron or sulfate reducing. Small-subunit rRNA genes we...

The effects of elevated atmospheric CO2 concentration on soil microbial communities have been previously recorded. However, limited information is available regarding the response of methanogenic communities to elevated CO2 in freshwater marshes. Using high-throughput sequencing and real-time quantitative PCR, we compared the abundance and community structure of methanogens in different compart...

Methane production by Methanothrix soehngenii VNBF grown on acetate (50 mM) as the sole carbon and energy source was influenced by the addition of Fe, trace elements, and pesticides. The addition of Fe and trace elements significantly enhanced the rate of CH(4) production. The addition of pesticides in the early growth phase caused complete inhibition. However, less inhibition was noted when pe...

Submarine mud volcanoes are a significant source of methane to the atmosphere. The Napoli mud volcano, situated in the brine-impacted Olimpi Area of the Eastern Mediterranean Sea, emits mainly biogenic methane particularly at the centre of the mud volcano. Temperature gradients support the suggestion that Napoli is a cold mud volcano with moderate fluid flow rates. Biogeochemical and molecular ...

Methanogenic Archaea are found in a wide range of environments and use several strategies to adjust to changes in extracellular solute concentrations. One methanogenic archaeon, Methanosarcina thermophila TM-1, can adapt to various osmotic conditions by synthesis of alpha-glutamate and a newly discovered compatible solute, Ne-acetyl-beta-lysine, or by accumulation of glycine betaine (betaine) a...

The physico-chemical characteristics of methanogenic granules are one of the most important properties for the successful operation of upflow anaerobic sludge blanket, since they could directly affect the substrate and nutrient transportation into granules. In this study, the effect of low strength ultrasonication on the settling velocity, permeability, porosity, and fluid collection efficiency...