−− A steady state model of an anaerobic methanogenic biofilm reactor-module that accounts for the biological interactions of four microbial groups, ionic equilibrium in solution, gas-liquid transfer phenomena and biofilm processes is presented. The model consists of a continuous stirred tank reactor type that allocates an inert support material, whose specific surface is taken into account. The...

Ammonia is a major environmental factor influencing biomethanation in full-scale anaerobic digesters. In this study, the effect of different ammonia levels on methanogenic pathways and methanogenic community composition of full-scale biogas plants was investigated. Eight full-scale digesters operating under different ammonia levels were sampled, and the residual biogas production was followed i...

Methanogenic aggregates, harvested from an upflow anaerobic sludge blanket reactor treating potato starch wastewater, were acclimatized to either glucose or a mixture of sugars and organic nitrogen compounds (i.e., diluted molasses). Both types of granules exhibited internal pH and substrate concentration gradients in mineral medium (pH 7.0, 30 degrees C) as was measured with microelectrodes. G...

Strictly anaerobic bacteria such as methanogenic, sulfate-reducing, and homoacetogenic bacteria could be enriched from all five oxic soils tested. The number of cells was lower than that in typical anoxic habitats. Spores did not always dominate the population of sulfate-reducing bacteria. In all soils, the methanogenic population displayed a long lag phase after anoxic conditions were imposed ...

Methanoregula formicica SMSP(T) is a mesophilic H2/formate-utilizing methanogenic archaeon and a representative of the family Methanoregulaceae, a recently proposed novel family within the order Methanomicrobiales. Here, we report a 2.8-Mb complete genome sequence of this methanogenic archaeon.

Hydrogen produced during colonic fermentation may be excreted, or removed by H2 consuming bacteria such as methanogenic and sulphate reducing bacteria. In vitro, sulphate reducing bacteria compete with methanogenic bacteria for hydrogen when sulphate is present. In this study the hypothesis that sulphate in the diet could alter CH4 production in vivo has been tested. Six methane excreting volun...

To gain insight into the mechanisms controlling methanogenic pathways in the Florida Everglades, the distribution and functional activities of methanogens and sulfate-reducing prokaryotes (SRPs) were investigated in soils (0 to 2 or 0 to 4 cm depth) across the well-documented nutrient gradient in the water conservation areas (WCAs) caused by runoff from the adjacent Everglades Agricultural Area...