Knowledge of the microbial consortia participating in the generation of biogas, especially in methane formation, is still limited. To overcome this limitation, the methanogenic archaeal communities in six full-scale biogas plants supplied with different liquid manures and renewable raw materials as substrates were analyzed by a polyphasic approach. Fluorescence in situ hybridization (FISH) was ...

Methanogenic archaea are widespread anaerobic microorganisms responsible for the production of biogenic methane. Several new species of psychrotolerant methanogenic archaea were recently isolated from a permafrost-affected soil in the Lena Delta (Siberia, Russia), showing an exceptional resistance against desiccation, osmotic stress, low temperatures, starvation, UV and ionizing radiation when ...

Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarb...

Tetracycline antibiotic wastewater with high chemical oxygen demand (COD) concentration and containing bio-refractory compounds was investigated in a lab-scale up-flow anaerobic sludge blanket (UASB) anoxic-oxic (A/O) reactor. Specific methanogenic activity (SMA) determined to reveal the inhibition levels of methane production volatile fatty acid (VFA) accumulation. The results showed that micr...

BACKGROUND Methanobrevibacter smithii, Methanobrevibacter oralis, Methanosphaera stadtmanae, Methanomassilicoccus luminyensis and Methanobrevibacter arboriphilicus have been cultured from human digestive microbiota. Each one of these fastidious methanogenic archaea requires a specific medium for its growth, hampering their routine isolation and the culture. METHODOLOGY/PRINCIPAL FINDINGS A ne...

UNLABELLED Hydrogenotrophic methanogenic Archaea require reduced ferredoxin as an anaplerotic source of electrons for methanogenesis. H(2) oxidation by the hydrogenase Eha provides these electrons, consistent with an H(2) requirement for growth. Here we report the identification of alternative pathways of ferredoxin reduction in Methanococcus maripaludis that operate independently of Eha to sti...

Cellulase activity measured as filter paper digesting activity (FPase) and carboxymethyl cellulase (CMCase) was demonstrated in hindgut extracts of the cockroach Periplaneta americana. The highest activities measured amounted to 0.89 and 0.12 U . ml for CMCase and FPase, respectively. The cellulolytic capacity of the hindgut population increased dramatically when protozoa were present, and the ...