Topic
Methanogen
About: Methanogen is a research topic. Over the lifetime, 1146 publications have been published within this topic receiving 48254 citations.
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01 Jun 2004
TL;DR: This work has shown that methanogenesis in peatlands is driven by methane, and the presence of methane-like particles in the strata of peatland strata is a clue to the establishment of phylogeny.
Abstract: 5 INTRODUCTION 7 Methanogenic Archaea 8 Taxonomy and phylogeny 8 Ecological diversity 10 Methanogenesis in peatlands 10 Peatlands 10 Substrate for methanogenesis 11 Anoxic degradation of organic matter 11 Vascular plants below-ground production 13 Methanogens in peatlands 14 Methanogenic activity 14 Methanogen communities 14 Pathways for methanogenesis 16 Molecular markers 16 Methyl-coenzyme M reductase gene 17 Small subunit 16S ribosomal RNA (16SrRNA) 18 AIMS OF THE STUDY 20 MATERIAL AND METHODS 21 Sites and sampling 21 Salmisuo site 21 Muhos site 21 Methods 21 RESULTS AND DISCUSSION 23 Potential methane production 23 Fen cluster, a new group of uncultured methanogens 23 Depth related variations of communities 24 mcrA analysis 24 16SrRNA analysis 25 Site related variations of communities 26 Primer efficiency 27 SUMMARY AND CONCLUDING REMARKS 28 ACKNOWLEDGMENTS 29 REFERENCES 30
10 citations
TL;DR: The methanogens were found to be to some extent radiation resistant when subjected to irradiation at small doses for short duration and no or marginal improvement of methane production occurred for the two strains TDM and TRM.
Abstract: Biomethanation is one of the desirable options for obtaining clean fuel from abundant renewable biomass resources. Improvement of biomethane production may be achieved by using improved strains of microbes, particularly the terminal microbes – the methanogens. Attempts have been made to improve the efficiency of the methanogens isolated from local sources by subjecting the methanogens to mutagenic changes by physical (by γ irradiation, neutron bombardment) or chemical (by addition of chemicals like acridine orange, colchicine) means. The effects of the treated methanogens on biomethanation were studied. γ Irradiation or neutron bombardment mutagenesis was dose-dependent and time-dependent. High doses proved to be lethal but methanogens were found to be to some extent radiation resistant when subjected to irradiation at small doses for short duration (∼5–10 s). No or marginal improvement of methane production occurred for the two strains TDM and TRM. Improvement of methane production occurred from successive transfers of radiation treated strain SSM. Chemical mutagens invariably inhibited biomethanation and the inhibition was dose dependent.
10 citations
TL;DR: In this article, the authors examined the interactions between bituminous coal and methanogenic microbial communities sourced from the goaf of a Bowen Basin underground coal mine and pure cultures of methanogens.
10 citations
TL;DR: In this article , a mesophilic batch test was conducted using four seeds collected from different digesters treating various combinations of substrates to investigate their effects on anaerobic digestion of fish waste degradation.
10 citations
TL;DR: Pine needles and ginkgo leaves extracts appear to have properties that decrease methanogenesis by inhibiting protozoa species and may have a potential for use as additives for ruminants.
Abstract: The effect on methanogens attached to the surface of rumen ciliate protozoa by the addition of plant extracts (pine needles and ginkgo leaves) was studied with particular reference to their effectiveness for decreasing methane emission. The plant extracts (pine needles and ginkgo leaves) were added to an in vitro fermentation incubated with rumen fluid. The microbial population including bacteria, ciliated-associated methanogen, four different groups of methanogens and Fibrobacter succinogenes were quantified by using the real-time PCR. Gas profiles including methane, carbon dioxide and hydrogen, and runinal fermentation characteristics were observed in vitro. The methane emission from samples with an addition of individual juices from pine needles, ginkgo leaves and 70% ethanol extract from ginko leaves was significantly lower (p<0.05, 27.1, 28.1 and 28.1 vs 34.0 ml/g DM) than that of the control, respectively. Total VFAs in samples with an addition of any of the plant extracts were significantly lower than that of the control (p<0.05) as well. The order Methanococcales and the order Methanosarcinales were not detected by using PCR in any incubated mixtures. The ciliate-associated methanogens population decreased from 25% to 49% in the plant extacts as compared to control. We speculate that the supplementation of juice from pine needles and ginkgo leaves extract (70% ethanol extract) decreased the protozoa population resulting in a reduction of methane emission in the rumen and thus inhibiting methanogenesis. The order Methanobacteriales community was affected by addition of all plant extracts and decreased to less than the control, while the order Methanomicrobiales population showed an increase to more than that of the control. The F. succinogenes, the major fibrolytic microorganism, population in all added plant extracts was increased to greater than that of the control. In conclusion, pine needles and ginkgo leaves extracts appear to have properties that decrease methanogenesis by inhibiting protozoa species and may have a potential for use as additives for ruminants.
9 citations