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1.
Cereal distillers grains, a by-product from bioethanol industry, proved to be a suitable feedstock for biogas production in
laboratory scale anaerobic digesters. Five continuously stirred tank reactors were run under constant conditions and monitored
for biogas production and composition along with other process parameters. Iron additives for sulfide precipitation significantly
improved the process stability and efficiency, whereas aerobic pretreatment of the grains had no effect. The microbial communities
in the reactors were investigated for their phylogenetic composition by terminal restriction fragment length polymorphism
analysis and sequencing of 16S rRNA genes. The bacterial subcommunities were highly diverse, and their composition did not
show any correlation with reactor performance. The dominant phylotypes were affiliated to the Bacteroidetes. The archaeal
subcommunities were less diverse and correlated with the reactor performance. The well-performing reactors operated at lower
organic loading rates and amended with iron chloride were dominated by aceticlastic methanogens of the genus Methanosaeta. The well-performing reactor operated at a high organic loading rate and supplemented with iron hydroxide was dominated by
Methanosarcina ssp. The reactor without iron additives was characterized by propionate and acetate accumulation and high hydrogen sulfide
content and was dominated by hydrogenotrophic methanogens of the genus Methanoculleus. 相似文献
2.
Two highly enriched cultures containing Dehalococcoides spp. were used to study the effect of aceticlastic methanogens on reductive vinyl chloride (VC) dechlorination. In terms of aceticlastic methanogens, one culture was dominated by Methanosaeta, while the other culture was dominated by Methanosarcina, as determined by fluorescence in situ hybridization. Cultures amended with 2-bromoethanesulfonate (BES), an efficient inhibitor of methanogens, exhibited slow VC dechlorination when grown on acetate and VC. Methanogenic cultures dominated by Methanosaeta had no impact on dechlorination rates, compared to BES-amended controls. In contrast, methanogenic cultures dominated by Methanosarcina displayed up to sevenfold-higher rates of VC dechlorination than their BES-amended counterparts. Methanosarcina-dominated cultures converted a higher percentage of [2- 14C]acetate to 14CO 2 when concomitant VC dechlorination took place, compared to nondechlorinating controls. Respiratory indices increased from 0.12 in nondechlorinating cultures to 0.51 in actively dechlorinating cultures. During VC dechlorination, aqueous hydrogen (H 2) concentrations dropped to 0.3 to 0.5 nM. However, upon complete VC consumption, H 2 levels increased by a factor of 10 to 100, indicating active hydrogen production from acetate oxidation. This process was thermodynamically favorable by means of the extremely low H 2 levels during dechlorination. VC degradation in nonmethanogenic cultures was not inhibited by BES but was limited by the availability of H 2 as electron donor, in cultures both with and without BES. These findings all indicate that Methanosarcina (but not Methanosaeta), while cleaving acetate to methane, simultaneously oxidizes acetate to CO 2 plus H 2, driving hydrogenotrophic dehalorespiration of VC to ethene by Dehalococcoides. 相似文献
3.
This study characterized the microbial community and population dynamics in an anaerobic hybrid reactor (AHR) treating cassava
starch wastewater. Methanogens and nonmethanogens were followed during the start-up and operation of the reactor, and linked
to operational and performance data. Biomass samples taken from the sludge bed and packed bed zones of the AHR at intervals
throughout the operational period were examined by 16S rRNA fluorescence in situ hybridization (FISH). The start-up seed and the reactor biomass were sampled during the feeding of the wastewater with a
chemical oxygen demand (COD) value of 8 g L −1 and a hydraulic retention time (HRT) of 8 days. These samples were characterized by the predominance of cells with long-rod
morphology similar to Methanosaeta spp. Following a sharp operational change, accomplished by increasing the COD concentration of the organic influent from
8 to 10 g L −1 and reducing the HRT from 8 to 5 days, there was a doubling of the organic loading rate, a reduction of the COD removal efficiency,
as well as decreased methane content in the biogas and an accumulation of total volatile acids in the reactor. Moreover, this
operational change resulted in a significant population shift from long-rod Methanosaeta-like cells to tetrad-forming Methanosarcina-like cells. The distributions of microbial populations involved in different zones of the AHR were determined. The results
showed that nonmethanogens became the predominant population in both sludge and the packed bed zone. However, the percentage
of methanogens in the packed bed zone was higher than that in the sludge bed zone. This higher percentage of methanogens was
likely caused by the fact that the packed bed zone provided a suitable environmental condition with an appropriate nutrient
availability for methanogen growth. 相似文献
4.
Anaerobic digestion is a sustainable technology for the treatment of organic waste and production of biogas. Acetoclastic methanogenesis accounts for the majority of methane production in anaerobic digestion. Therefore, sustaining robust acetoclastic methanogens is important for stable process performance. Due to faster growth kinetics at high acetate concentrations, it has been considered that Methanosarcina would be more prevalent than Methanosaeta in unstable anaerobic digestion processes which frequently experience high acetate levels. Methanogen population dynamics were monitored in multiple continuous anaerobic digesters for 500 days. Results from quantitative polymerase chain reaction analysis show that Methanosaeta dominated over Methanosarcina in anaerobic digestion at high acetate levels up to 44 mM, suggesting the potential of Methanosaeta as a robust and efficient acetoclastic candidate for resilient anaerobic methane conversion. Further efforts are needed to identify mechanisms contributing to the unexpected competitiveness of these methanogens at high acetate levels observed in this study. 相似文献
5.
Taking into account isotope 13C value a mathematical model was developed to describe the dynamics of methanogenic population during mesophilic anaerobic
digestion of putrescible solid waste and waste imitating Chinese municipal solid waste. Three groups of methanogens were considered
in the model including unified hydrogenotrophic methanogens and two aceticlastic methanogens Methanosaeta sp. and Methanosarcina sp. It was assumed that Methanosaeta sp. and Methanosarcina sp. are inhibited by high volatile fatty acids concentration. The total organic and inorganic carbon concentrations, methane
production, methane and carbon dioxide partial pressures as well as the isotope 13C incorporation in PSW and CMSW were used for the model calibration and validation. The model showed that in spite of the
high initial biomass concentration of Methanosaeta sp. Methanosarcina sp. became the dominant aceticlastic methanogens in the system. This prediction was confirmed by FISH. It is concluded that
Methanosarcina sp. forming multicellular aggregates may resist to inhibition by volatile fatty acids (VFAs) because a slow diffusion rate
of the acids limits the VFA concentrations inside the Methanosarcina sp. aggregates. 相似文献
6.
A dual approach consisting of cultivation and molecular retrieval of partial archaeal 16S rRNA genes was carried out to characterize the diversity and structure of the methanogenic community inhabiting the anoxic bulk soil of flooded rice microcosms. The molecular approach identified four groups of known methanogens. Three environmental sequences clustered with Methanobacterium bryantii and Methanobacterium formicicum, six were closely related but not identical to those of strains of Methanosaeta concilii, two grouped with members of the genus Methanosarcina, and two were related to the methanogenic endosymbiont of Plagiopyla nasuta. The cultivation approach via most-probable-number counts with a subsample of the same soil as an inoculum yielded cell numbers of up to 10 7 per g of dry soil for the H 2-CO 2-utilizing methanogens and of up to 10 6 for the acetate-utilizing methanogens. Strain VeH52, isolated from the terminal positive dilution on H 2-CO 2, grouped within the phylogenetic radiation characterized by M. bryantii and M. formicicum and the environmental sequences of the Methanobacterium-like group. A consortium of two distinct methanogens grew in the terminal positive culture on acetate. These two organisms showed absolute 16S rRNA gene identities with environmental sequences of the novel Methanosaeta-like group and the Methanobacterium-like group. Methanosarcina spp. were identified only in the less-dilute levels of the same dilution series on acetate. These data correlate well with acetate concentrations of about 11 μM in the pore water of this rice paddy soil. These concentrations are too low for the growth of known Methanosarcina spp. but are at the acetate utilization threshold of Methanosaeta spp. Thus, our data indicated Methanosaeta spp. and Methanobacterium spp. to be the dominant methanogenic groups in the anoxic rice soil, whereas Methanosarcina spp. appeared to be less abundant. 相似文献
7.
Acetoclastic methanogenesis is a key metabolic process in anaerobic digestion, a technology with broad applications in biogas production and waste treatment. Acetoclastic methanogenesis is known to be performed by two archaeal genera, Methanosaeta and Methanosarcina. The conventional model posits that Methanosaeta populations are more competitive at low acetate levels (<1 mM) than Methanosarcina and vice versa at higher acetate concentrations. While this model is supported by an extensive body of studies, reports of inconsistency have grown that Methanosaeta were observed to outnumber Methanosarcina at elevated acetate levels. In this study, monitoring of anaerobic digesters treating animal wastewater unexpectedly identified Methanosaeta as the dominant acetoclastic methanogen population at both low and high acetate levels during organic overloading. The surprising competitiveness of Methanosaeta at elevated acetate was further supported by the enrichment of Methanosaeta with high concentrations of acetate (20 mM). The dominance of Methanosaeta in the methanogen community could be reproduced in anaerobic digesters with the direct addition of acetate to above 20 mM, again supporting the competitiveness of Methanosaeta over Methanosarcina at elevated acetate levels. This study for the first time systematically demonstrated that the dominance of Methanosaeta populations in anaerobic digestion could be linked to the competitiveness of Methanosaeta at elevated acetate concentrations. Given the importance of acetoclastic methanogenesis in biological methane production, findings from this study could have major implications for developing strategies for more effective control of methanogenic treatment processes. 相似文献
8.
Thermophilic dry anaerobic digestion of sludge for cellulose methanization was acclimated at 53 °C for nearly 5 years using
a waste paper-based medium. The stability of the microbial community structure and the microbial community responsible for
the cellulose methanization were studied by 16S rRNA gene-based clone library analysis. The microbial community structure
remained stable during the long-term acclimation period. Hydrogenotrophic methanogens dominated in methanogens and Methanothermobacter, Methanobacterium, Methanoculleus, and Methanosarcina were responsible for the methane production. Bacteria showed relatively high diversity and distributed mainly in the phyla
Firmicutes, Bacteroidetes, and Synergistetes. Ninety percent of operational taxonomic units (OTUs) were affiliated with the phylum Firmicutes, indicating the crucial roles of this phylum in the digestion. Relatives of Clostridium stercorarium, Clostridium thermocellum, and Halocella cellulosilytica were dominant cellulose degraders. The acclimated stable sludge was used to treat garbage stillage discharged from a fuel
ethanol production process, and the shift of microbial communities with the change of feed was analyzed. Both archaeal and
bacterial communities had obviously changed: Methanoculleus spp. and Methanothermobacter spp. and the protein- and fatty acid-degrading bacteria became dominant. Accumulation of ammonia as well as volatile fatty
acids led to the inhibition of microbial activity and finally resulted in the deterioration of methane fermentation of the
garbage stillage. 相似文献
9.
The presence of methanogens of the genera Methanosarcina and Methanosaeta, and the family Methanomicrobiaceae, and the absence of the family Methanobacteriaceae were inferred from the analysis of lipid component parts in three kinds of sludge from two anaerobic digestors by comparison with the distribution of the lipid component parts among 31 species of methanogens previously reported. 相似文献
10.
We constructed two mesophilic anaerobic chemostats that were continuously fed with synthetic wastewater containing butyrate
as the sole source of carbon and energy. Steady-state conditions were achieved at dilution rates between 0.025 and 0.7 day −1. Butyrate, fed into the chemostat, was almost completely mineralized to CH 4 and CO 2 at dilution rates below 0.5 day −1. The butyrate-degrading methanogenic communities in the chemostats at dilution rates between 0.025 and 0.7 day −1 were monitored based on the 16S rRNA gene, using molecular biological techniques including clone library analysis, denaturing
gradient gel electrophoresis, and quantitative real-time polymerase chain reaction. The aceticlastic methanogen Methanosaeta and the hydrogenotrophic methanogen Methanoculleus dominated in methanogens at low dilution rates, whereas the aceticlastic methanogen Methanosaeta, Methanosarcina, the hydrogenotrophic methanogen Methanoculleus, and Methanospirillum dominated at high dilution rates. Bacteria affiliated with the family Syntrophaceae in the phylum Proteobacteria predominated at the low dilution rate of 0.025 day −1, whereas bacteria affiliated with the phylum Firmicutes and Candidate division OP3 predominated at high dilution rates. A significant quantity of bacteria closely related to the
genus Syntrophomonas was detected at high dilution rates. Dilution rate showed an apparent effect on archaeal and bacterial communities in the
butyrate-fed chemostats. 相似文献
11.
The community structure of methanogenic Archaea on anoxically incubated rice roots was investigated by amplification, sequencing, and phylogenetic analysis of 16S rRNA and methyl-coenzyme M reductase ( mcrA) genes. Both genes demonstrated the presence of Methanomicrobiaceae, Methanobacteriaceae, Methanosarcinaceae, Methanosaetaceae, and Rice cluster I, an uncultured methanogenic lineage. The pathway of CH 4 formation was determined from the 13C-isotopic signatures of the produced CH 4, CO 2 and acetate. Conditions and duration of incubation clearly affected the methanogenic community structure and the pathway of CH 4 formation. Methane was initially produced from reduction of CO 2 exclusively, resulting in accumulation of millimolar concentrations of acetate. Simultaneously, the relative abundance of the acetoclastic methanogens (Methanosarcinaceae, Methanosaetaceae), as determined by T-RFLP analysis of 16S rRNA genes, was low during the initial phase of CH 4 production. Later on, however, acetate was converted to CH 4 so that about 40% of the produced CH 4 originated from acetate. Most striking was the observed relative increase of a population of Methanosarcina spp. (but not of Methanosaeta spp.) briefly before acetate concentrations started to decrease. Both acetoclastic methanogenesis and Methanosarcina populations were suppressed by high phosphate concentrations, as observed under application of different buffer systems. Our results demonstrate the parallel change of microbial community structure and function in a complex environment, i.e., the increase of acetoclastic Methanosarcina spp. when high acetate concentrations become available. 相似文献
12.
Biogas is a renewable energy resource produced during the anaerobic digestion of various organic substrates. A wide community of microorganisms is involved, including methanogens. These Archaea are the biologic key to the process because they accomplish the methane-forming reaction. Despite its crucial role, the microbiome inside the digester is poorly understood. The aim of this work is to develop bioindicators of efficiency for the anaerobic process through the quantification and characterisation of the methanogens and sulphate-reducing bacteria. From a full-scale digester fed with organic wastes, 31 samples were collected. Temperature, pH, acidity, alkalinity and biogas quantity and quality were monitored over time. The methanogens were detected from the samples both in total and as belonging to different taxa units. These evaluations, by real-time quantitative PCR (RT-qPCR) methods, produced valuable results for Methanosarcina, Methanosaeta, Methanocorpusculaceae and sulphate-reducing bacteria. Methanosarcina was the most abundant family, followed by Methanocorpusculaceae and then Methanosaeta. The methanogen taxa are significantly and directly correlated with each other ( p?<?0.05). Methanosaeta and Methanocorpusculaceae are present in significantly different amounts at different temperatures. While Methanosaeta levels also change when the organic load increases ( t test, p?<?0.05), Methanosarcina is more tolerant, and its levels are quite constant. Methanosarcina and Methanosaeta are proposed to be bioindicators of the stability of the process (the first) and of susceptibility (the second) to detect early sufferance conditions in the digester. These methods will be useful in the control and optimisation of an eco-friendly waste-to-energy system. 相似文献
13.
We investigated microbial methanogenesis and community structure based on 16S rRNA gene sequences from a coal seam aquifer located 843–907 m below ground level in northern Japan; additionally, we studied the δ 13C and δ 2H (δD) of coal‐bed gases and other physicochemical parameters. Although isotopic analysis suggested a thermocatalytic origin for the gases, the microbial activity and community structure strongly implied the existence of methanogenic microbial communities in situ. Methane was generated in the enrichment cultures of the hydrogenotrophic and methylotrophic microorganisms obtained from coal seam groundwater. Methanogen clones dominated the archaeal 16S rRNA gene libraries and were mostly related to the hydrogenotrophic genus Methanoculleus and the methylotrophic genus Methanolobus. Bacterial 16S rRNA gene libraries were dominated by the clones related to the genera Acetobacterium and Syntrophus which have a symbiotic association with methanogens. LIBSHUFF analysis revealed that N 2 gas injected into the coal seam (for enhanced methane production) does not affect the coverage of archaeal and bacterial populations. However, amova analysis does provide evidence for a change in the genetic diversity of archaeal populations that are dominated by methanogens. Therefore, N 2 injection into the coal seam might affect the cycling of matter by methanogens in situ. 相似文献
14.
To enrich syntrophic acetate‐oxidizing bacteria (SAOB), duplicate chemostats were inoculated with sludge from syntrophic acetate oxidation (SAO)‐dominated systems and continuously supplied with acetate (0.4 or 7.5 g l ?1) at high‐ammonia levels. The chemostats were operated under mesophilic (37°C) or thermophilic (52°C) temperature for about six hydraulic retention times (HRT 28 days) and were sampled over time. Irrespective of temperature, a methane content of 64–69% and effluent acetate level of 0.4–1.0 g l ?1 were recorded in chemostats fed high acetate. Low methane production in the low‐acetate chemostats indicated that the substrate supply was below the threshold for methanization of acetate via SAO. Novel representatives within the family Clostridiales and genus Syntrophaceticus (class Clostridia) were identified to represent putative SAOB candidates in mesophilic and thermophilic conditions respectively. Known SAOB persisted at low relative abundance in all chemostats. The hydrogenotrophic methanogens Methanoculleus bourgensis (mesophilic) and Methanothermobacter thermautotrophicus (thermophilic) dominated archaeal communities in the high‐acetate chemostats. In line with the restricted methane production in the low‐acetate chemostats, methanogens persisted at considerably lower abundance in these chemostats. These findings strongly indicate involvement in SAO and tolerance to high ammonia levels of the species identified here, and have implications for understanding community function in stressed anaerobic processes. 相似文献
15.
The deposition of mine tailings generated from 125 years of sulfidic ore mining resulted in the enrichment of Coeur d'Alene
River (CdAR) sediments with significant amounts of toxic heavy metals. A review of literature suggests that microbial populations
play a pivotal role in the biogeochemical cycling of elements in such mining-impacted sedimentary environments. To assess
the indigenous microbial communities associated with metal-enriched sediments of the CdAR, high-density 16S microarray (PhyloChip)
and clone libraries specific to bacteria (16S rRNA), ammonia oxidizers ( amoA), and methanogens ( mcrA) were analyzed. PhyloChip analysis provided a comprehensive assessment of bacterial populations and detected the largest
number of phylotypes in Proteobacteria followed by Firmicutes and Actinobacteria. Furthermore, PhyloChip and clone libraries displayed considerable metabolic diversity in indigenous microbial populations
by capturing several chemolithotrophic groups such as ammonia oxidizers, iron-reducers and -oxidizers, methanogens, and sulfate-reducers
in the CdAR sediments. Twenty-two phylotypes detected on PhyloChip could not be classified even at phylum level thus suggesting
the presence of novel microbial populations in the CdAR sediments. Clone libraries demonstrated very limited diversity of
ammonia oxidizers and methanogens in the CdAR sediments as evidenced by the fact that only Nitrosospira- and Methanosarcina-related phylotypes were retrieved in amoA and mcrA clone libraries, respectively. 相似文献
16.
The microbial communities (Bacteria and Archaea) established in an anaerobic fluidized bed reactor used to treat synthetic
vinasse (betaine, glucose, acetate, propionate, and butyrate) were characterized by denaturing gradient gel electrophoresis
(DGGE) and phylogenetic analysis. This study was focused on the competitive and syntrophic interactions between the different
microbial groups at varying influent substrate to sulfate ratios of 8, 4, and 2 and anaerobic or micro-aerobic conditions.
Acetogens detected along the anaerobic phases at substrate to sulfate ratios of 8 and 4 seemed to be mainly involved in the
fermentation of glucose and betaine, but they were substituted by other sugar or betaine degraders after oxygen application.
Typical fatty acid degraders that grow in syntrophy with methanogens were not detected during the entire reactor run. Likely,
sugar and betaine degraders outnumbered them in the DGGE analysis. The detected sulfate-reducing bacteria (SRB) belonged to
the hydrogen-utilizing Desulfovibrio. The introduction of oxygen led to the formation of elemental sulfur (S 0) and probably other sulfur compounds by sulfide-oxidizing bacteria (γ- Proteobacteria). It is likely that the sulfur intermediates produced from sulfide oxidation were used by SRB and other microorganisms as
electron acceptors, as was supported by the detection of the sulfur respiring Wolinella succinogenes. Within the Archaea population, members of Methanomethylovorans and Methanosaeta were detected throughout the entire reactor operation. Hydrogenotrophic methanogens mainly belonging to the genus Methanobacterium were detected at the highest substrate to sulfate ratio but rapidly disappeared by increasing the sulfate concentration. 相似文献
17.
Air-side stripping without a prior solid–liquid phase separation step is a feasible and promising process to control ammonia concentration in thermophilic digesters. During the process, part of the anaerobic biomass is exposed to high temperature, high pH and aerobic conditions. However, there are no studies assessing the effects of those harsh conditions on the microbial communities of thermophilic digesters. To fill this knowledge gap, the microbiomes of two thermophilic digesters (55°C), fed with a mixture of pig manure and nitrogen-rich co-substrates, were investigated under different organic loading rates (OLR: 1.1–5.2 g COD l −1 day −1), ammonia concentrations (0.2–1.5 g free ammonia nitrogen l −1) and stripping frequencies (3–5 times per week). The bacterial communities were dominated by Firmicutes and Bacteroidetes phyla, while the predominant methanogens were Methanosarcina sp archaea. Increasing co-substrate fraction, OLR and free ammonia nitrogen (FAN) favoured the presence of genera Ruminiclostridium, Clostridium and Tepidimicrobium and of hydrogenotrophic methanogens, mainly Methanoculleus archaea. The data indicated that the use of air-side stripping did not adversely affect thermophilic microbial communities, but indirectly modulated them by controlling FAN concentrations in the digester. These results demonstrate the viability at microbial community level of air side-stream stripping process as an adequate technology for the ammonia control during anaerobic co-digestion of nitrogen-rich substrates. 相似文献
18.
This study was conducted to analyze the methanogen population in a corrosive marine biofilm based on 16S rDNA analysis, using a PCR-cloning-sequencing approach. There were 80 methanogen clones developed from the PCR-amplified DNA extracted from the biofilm on the mild steel surface. All clones were categorized into one of five operational taxonomy units (OTUs). Two OTUs (comprising 57 clones) were affiliated with the acetotrophic Methanosaeta genus; the remaining three OTUs (23 clones) were affiliated with the hydrogenotrophic genera of Methanogenium, Methanoplanus and Methanocalculus. The hydrogenotrophic methanogens could directly cause metal corrosion through cathodic depolarization, whereas the acetotrophic methanogens grew syntrophically with corrosion-causing sulfate-reducing bacteria, as observed by fluorescent in situ hybridization, and thus contribute indirectly to metal corrosion. 相似文献
19.
The microbial communities present in two underground coal mines in the Bowen Basin, Queensland, Australia, were investigated to deduce the effect of pumping and mining on subsurface methanogens and methanotrophs. The micro‐organisms in pumped water from the actively mined areas, as well as, pre‐ and post‐mining formation waters were analyzed using 16S rRNA gene amplicon sequencing. The methane stable isotope composition of Bowen Basin coal seam indicates that methanogenesis has occurred in the geological past. More recently at the mine site, changing groundwater flow dynamics and the introduction of oxygen in the subsurface has increased microbial biomass and diversity. Consistent with microbial communities found in other coal seam environments, pumped coal mine waters from the subsurface were dominated by bacteria belonging to the genera Pseudomonas and the family Rhodocyclaceae. These environments and bacterial communities supported a methanogen population, including Methanobacteriaceae, Methanococcaceae and Methanosaeta. However, one of the most ubiquitous micro‐organisms in anoxic coal mine waters belonged to the family ‘ Candidatus Methanoperedenaceae’. As the Archaeal family ‘ Candidatus Methanoperedenaceae’ has not been extensively defined, the one studied species in the family is capable of anaerobic methane oxidation coupled to nitrate reduction. This introduces the possibility that a methane cycle between archaeal methanogenesis and methanotrophy may exist in the anoxic waters of the coal seam after hydrogeological disturbance. 相似文献
20.
Different methods were applied to study the role of aceticlastic methanogens in biogas reactors treating solid waste and wastewater. We used traditional microbiological methods, immunological and 16S rRNA ribosomal probesfor detection of the methanogens. Using this approach we identified themethanogenic spp. and their activity. In biofilm system, such as the UASBreactors the presence of the two aceticlastic methanogens could be correlatedto the difference in the kinetic properties of the two species. In biogas reactor treating solid wastes, such as manure or mixture of manure and organic industrial waste, only Methanosarcina spp. were identified. Methanosarcina spp. isolated from different plants had different kinetics depending on their origin. Relating the reactor performance data to measurement of the activity by conventional microbiological methods gave a good indication of the microbial status of specific trophic groups. 16S rRNA probing confirmed these observation and gave a more detailed picture of the microbial groups present. 相似文献
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