Methanogenesis in sediments from deep lakes at different temperatures (2–70°C)

1997 ◽  
Vol 36 (6-7) ◽  
pp. 57-64 ◽  
Author(s):  
Alla N. Nozhevnikova ◽  
C. Holliger ◽  
A. Ammann ◽  
A. J. B. Zehnder
Keyword(s):  
Organic Matter ◽  
Microbial Communities ◽  
Methane Production ◽  
Low Temperatures ◽  
Main Question ◽  
Deep Lakes ◽  
Temperature Range ◽  
Wide Range ◽  
Thermophilic Conditions ◽  
Different Temperatures

Methanogenic degradation of organic matter occurs in a wide temperature range from psychrophilic to extreme thermophilic conditions. Mesophilic and thermophilic methanogenesis is relatively well investigated, but little is known about low temperature methanogenesis and psychrophilic methanogenic communities. The aim of the present work was to study methanogenesis in a wide range of temperatures with samples from sediments of deep lakes. These sediments may be considered deposits of different types of microorganisms, which are constantly exposed to low temperatures. The main question was how psychrophilic methanogenic microbial communities compare to mesophilic and thermophilic ones. Methanogenesis in a temperature range of 2–70°C was investigated using sediment samples from Baldegger lake (65 m) and Soppen lake (25 m), Switzerland. Methane production from organic matter of sediments occurred at all temperatures tested. An exponential dependence of methane production rate was found between 2 and 30°C. Methanogenesis occurred even at 70°C. At the same time stable methane production from organic matter of sediments was observed at temperatures below 10°C. Methanogenic microbial communities were enriched at different temperatures. The communities enriched at 4–8°C had the highest activity at low temperatures indicating that a specific psychrophilic community exists. Addition of substrates such as cellulose, volatile fatty acids (butyrate, propionate, acetate), methanol and H2/CO2 stimulated methane production at all temperatures. H2/CO2 as well as methanol were directly converted to methane under thermophilic conditions. At low temperatures these substrates were converted to methane by a two-step process. First acetate was formed, followed by methane production from acetate. When acetate concentrations were high, acetoclastic methanogenesis was inhibited at low temperatures. This reaction appears to be one of the “bottle neck” in psychrophilic methanogenesis.

The cracking of cyclo pentene on a silica-alumina catalyst

1960 ◽  
Vol 257 (1288) ◽  
pp. 132-145 ◽  
Keyword(s):  
Molecular Weight ◽  
Catalytic Cracking ◽  
Slow Step ◽  
Static System ◽  
Surface Complexes ◽  
Temperature Range ◽  
Carbonium Ions ◽  
Wide Range ◽  
Different Temperatures ◽  
Silica Alumina

The cracking of cyclo pentene on silica-alumina was studied in a flow system over the temperature range 368 to 505 °C. The analysis of the products was carried out by gas-liquid chromatographic techniques and the design of the apparatus made it possible to measure the pressures of compounds of low molecular weight at a series of points along the catalyst bed. Partial analyses were made of the extremely wide range of products of high molecular weight collected at the end of the reactor for reactions at three different temperatures. The results obtained were sufficiently detailed to provide activation energies for the for­mation of a number of the products and for the decomposition of cyclo pentene and to per­mit the application of thermodynamical calculations to ascertain the source of substances such as cyclo pentane and methyl cyclo pentane. The results of the flow experiments together with a subsidiary experiment on the reactions which occurred to cyclo pentene at 68 °C on the catalyst in a static system indicated that the formation, polymerization and isomerization of the surface complexes to condensed six-membered ring systems must be extremely rapid processes in the temperature range required for the catalytic cracking of cyclo pentene. These processes probably occur through the formation of carbonium ions and consequently the formation of these ions is unlikely to be the slow step in the catalytic cracking of olefins. The rate of the cracking reaction may depend on the rate of decomposition of carbonium ions considerably larger in size than the original olefin.

scholarly journals On the behaviour of barnacles III. Further observations on the influence of temperature and age on cirral activity

1957 ◽  
Vol 36 (2) ◽  
pp. 323-334 ◽  
Author(s):  
A. J. Southward
Keyword(s):  
Age Groups ◽  
Wide Distribution ◽  
Tropical Species ◽  
Growth Rings ◽  
Temperature Range ◽  
Wide Range ◽  
Different Temperatures ◽  
Warm Temperate ◽  
Northern Species ◽  
Active Can

The range of temperature over which the cirri were active, and the frequency of beating of the cirri at different temperatures were measured in a further five species of barnacles from a variety of habitats. In three of the species the temperature range and frequency of cirral beat were related to the geographical distribution of the species. The tropical and warm temperate species Balanus amphitrite was active at higher temperatures, and showed a greater frequency of beating than the northern species B. balanus; conversely, the latter was active to much lower temperatures than JB. amphitrite. The species with the widest geographical range, B. improvisus, showed cirral activity over the widest range of temperatures, although its behaviour at high temperatures was similar to that of the related species B. amphitrite. It is suggested that B. improvisus is a tropical species that has adapted itself to colder climates; its tolerance of a wide range of temperatures may be associated with its tolerance of low salinities.The stalked barnacle Lepas anatifera showed too restricted a temperature range for its supposed world-wide distribution, and it is suggested that the species may contain physiological races adapted to different climates. The extremely restricted range of temperatures over which the cirri of the deepsea barnacle Hexelasma hirsutum were active can be correlated with the almost uniform temperature conditions at great depths.In B. balanus age-groups can be clearly distinguished by growth rings on the shell, and the cirral frequency was found to be slower in the older specimens. Even slower cirral beating was found in some starved specimens.

scholarly journals The anaerobic digestion microbiome: a collection of 1600 metagenome-assembled genomes shows high species diversity related to methane production

2019 ◽  
Author(s):  
Stefano Campanaro ◽  
Laura Treu ◽  
Luis M Rodriguez-R ◽  
Adam Kovalovszki ◽  
Ryan M Ziels ◽  
...  
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Metabolic Reconstruction ◽  
Waste Biomass ◽  
Dynamic Composition ◽  
Extensive Evaluation ◽  
Wide Range ◽  
Biogas Reactors ◽  
High Flexibility

AbstractBackgroundMicroorganisms in biogas reactors are essential for degradation of organic matter and methane production through anaerobic digestion process. However, a comprehensive genome-centric comparison, including relevant metadata for each sample, is still needed to identify the globally distributed biogas community members and serve as a reliable repository.ResultsHere, 134 publicly available datasets derived from different biogas reactors were used to recover 1,635 metagenome-assembled genomes (MAGs) representing different bacterial and archaeal species. All genomes were estimated to be >50% complete and nearly half were ≥90% complete with ≤5% contamination. In most samples, specialized microbial communities were established, while only a few taxa were widespread among the different reactor systems. Metabolic reconstruction of the MAGs enabled the prediction of functional traits related to biomass degradation and methane production from waste biomass. An extensive evaluation of the replication index provided an estimation of the growth rate for microbes involved in different steps of the food chain. The recovery of many MAGs belonging to Candidate Phyla Radiation and other underexplored taxa suggests their specific involvement in the anaerobic degradation of organic matter.ConclusionsThe outcome of this study highlights a high flexibility of the biogas microbiome. The dynamic composition and adaptability to the environmental conditions, including temperatures and a wide range of substrates, were demonstrated. Our findings enhance the mechanistic understanding of anaerobic digestion microbiome and substantially extend the existing repository of genomes. The established database represents a relevant resource for future studies related to this engineered ecosystem.

A novel fluxomics approach to decipher the flux partitioning between anabolic and catabolic processes in soil microbial communities

2020 ◽  
Author(s):  
Theresa Böckle ◽  
Yuntao Hu ◽  
Jörg Schnecker ◽  
Wolfgang Wanek
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Communities ◽  
Metabolic Pathways ◽  
Isotope Labeling ◽  
Soil Microbial Communities ◽  
Microbial Activities ◽  
Soil Microbial ◽  
Wide Range

<p>The activities of soil microorganisms drive soil carbon (C) and nutrient cycling and therefore play an important role in local and global terrestrial C dynamics and nutrient cycles. Unfortunately, soil microbial activities have been defined mostly by measurements of heterotrophic respiration, potential enzyme activities, or net N processes. However, soil microbial activities comprise more than just catabolic processes such as respiration and N mineralization. Recently anabolic processes (biosynthesis and growth) and the partitioning between anabolic and catabolic processes in soil microbial metabolism have gained more attention as they control microbial soil organic matter formation. Understanding the controls on these processes allows an improved understanding of the key roles that soil microbes play in organic matter decomposition (catabolic processes) and soil organic matter sequestration (anabolic processes leading to growth, biomass and necromass formation), and their potential feedback to global change.</p><p>Generally, there are two approaches to study the metabolism of soil microbial communities: First, position-specific isotope labeling is a tool that allows the tracing of <sup>13</sup>C-atoms in organic molecules on their way through the network of metabolic pathways and second, metabolomics and fluxomics approaches can enable disentangling the highly complex metabolic networks of microbial communities, which however have rarely (metabolomics) or never (fluxomics) been applied to soils.</p><p>In this study we developed a targeted soil metabolomics approach coupled to <sup>13</sup>C isotope tracing (fluxomics), in which we extract, purify and measure a preselected set of key metabolites. Our aim was to cover the wide spectrum of soil microbial metabolic pathways based on the analysis of biomarker metabolites being unique to specific metabolic pathways such as  glycolysis/gluconeogenesis (e.g. fructose 1,6-bisphosphate), the pentose phosphate pathway (ribose-5-phosphate), the citric acid cycle (α-ketoglutaric acid), purine and pyrimidine metabolism (UMP, AMP, allantoin), amino acid biosynthesis and degradation (10proteinogenic amino acids and their intermediates), the urea cycle (ornithine), amino sugar metabolism (N-Acetyl-D-Glucosamine and –muramic acid) and the shikimate pathway (shikimate). The minute concentrations of these primary metabolites are extracted from soils by 1 M KCl including 5 % chloroform, salts are removed by freeze-drying, methanol dissolution and cation-/anion-exchange chromatography and the metabolites and their isotopomers quantified by UPLC-Orbitrap mass spectrometry. To cover the wide range of metabolites, compound separations are performed by  hydrophilic interaction chromatography (HILIC) for metabolites such as amino acids, (poly-)amines, nucleosides and nucleobases and by Ion chromatography (IC), to separate charged molecules like amino sugars, sugar phosphates and organic acids.  Here we will show fluxomics results from a laboratory soil warming experiment where we added <sup>13</sup>C-glucose to a temperate forest soil as a proof of concept.</p>

scholarly journals Effect of time-temperature binomial in obtaining biochemical oxygen demand of different wastewaters

2014 ◽  
Vol 34 (2) ◽  
pp. 332-340 ◽  
Author(s):  
Mateus P. de Matos ◽  
Alisson C. Borges ◽  
Antonio T. de Matos ◽  
Edson F. da Silva ◽  
Mauro A. Martinez
Keyword(s):  
Organic Matter ◽  
Incubation Time ◽  
Biochemical Oxygen Demand ◽  
Oxygen Demand ◽  
Septic Tanks ◽  
Temperature Range ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Wastewater Samples ◽  
Biodegradable Organic Matter

Studies on the effects of temperature and time of incubation of wastewater samples for the estimation of biodegradable organic matter through the biochemical oxygen demand (BOD), that nowadays are rare, considering that the results of the classic study of STREETER & PHELPS(1925) have been accepted as standard. However, there are still questions how could be possible to reduce the incubation time; whether the coefficient of temperature (θ) varies with the temperature and with the type of wastewater and if it approaches 1.047. Aiming the elucidation of these questions, wastewater samples of dairy, swine and sewage treated in septic tanks were incubated at temperatures of 20, 30 and 35 °C, respectively for 5, 3.16 and 2.5 days. From the parameter of deoxygenation coefficient at 20 °C (k20), θ30 and θ35 were calculated. The results indicated that θ values changes with the type of wastewater, however does not vary in the temperature range between 30 and 35 °C, and that the use of 1.047 value did not implied significant differences in obtaining k in a determined T temperature. Thus, it is observed that the value of θ can be used to estimate the required incubation time of the samples at different temperatures.

scholarly journals Acetotrophic Activity Facilitates Methanogenesis from LCFA at Low Temperatures: Screening from Mesophilic Inocula

Archaea ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Suniti Singh ◽  
Johanna M. Rinta-Kanto ◽  
Riitta Kettunen ◽  
Piet Lens ◽  
Gavin Collins ◽  
...  
Keyword(s):  
Methane Production ◽  
Low Temperatures ◽  
Granular Sludge ◽  
Amplicon Sequencing ◽  
Anaerobic Treatment ◽  
Dairy Wastewater ◽  
Anaerobic Microorganisms ◽  
The Family ◽  
Thermophilic Conditions

The inoculum source plays a crucial role in the anaerobic treatment of wastewaters. Lipids are present in various wastewaters and have a high methanogenic potential, but their hydrolysis results in the production of long chain fatty acids (LCFAs) that are inhibitory to anaerobic microorganisms. Screening of inoculum for the anaerobic treatment of LCFA-containing wastewaters has been performed at mesophilic and thermophilic conditions. However, an evaluation of inocula for producing methane from LCFA-containing wastewater has not yet been conducted at low temperatures and needs to be undertaken. In this study, three inocula (one granular sludge and two municipal digester sludges) were assessed for methane production from LCFA-containing synthetic dairy wastewater (SDW) at low temperatures (10 and 20°C). A methane yield (based on mL-CH4/g-CODadded) of 86-65% with acetate and 45-20% with SDW was achieved within 10 days using unacclimated granular sludge, whereas the municipal digester sludges produced methane only at 20°C but not at 10°C even after 200 days of incubation. The acetotrophic activity in the inoculum was found to be crucial for methane production from LCFA at low temperatures, highlighting the role ofMethanosaeta(acetoclastic archaea) at low temperatures. The presence of bacterial taxa from the familySyntrophaceae(Syntrophusand uncultured taxa) in the inoculum was found to be important for methane production from SDW at 10°C. This study suggests the evaluation of acetotrophic activity and the initial microbial community characteristics by high-throughput amplicon sequencing for selecting the inoculum for producing methane at low temperatures (up to 10°C) from lipid-containing wastewaters.

scholarly journals New insights from the biogas microbiome by comprehensive genome-resolved metagenomics of nearly 1600 species originating from multiple anaerobic digesters

2019 ◽  
Author(s):  
Stefano Campanaro ◽  
Laura Treu ◽  
Luis M Rodriguez-Rojas ◽  
Adam Kovalovszki ◽  
Ryan M Ziels ◽  
...  
Keyword(s):  
Organic Matter ◽  
Methane Production ◽  
Metabolic Reconstruction ◽  
Waste Biomass ◽  
Anaerobic Digesters ◽  
Extensive Evaluation ◽  
Archaeal Species ◽  
Wide Range ◽  
Biogas Reactors ◽  
High Flexibility

Abstract Background Microorganisms in biogas reactors are essential for degradation of organic matter and methane production. However, a comprehensive genome-centric comparison, including relevant metadata for each sample, is still needed to identify the globally distributed biogas community members and serve as a reliable repository. Results Here, 134 publicly available metagenomes derived from different biogas reactors were used to recover 1,635 metagenome-assembled genomes (MAGs) representing different biogas bacterial and archaeal species. All genomes were estimated to be >50% complete and nearly half ≥90% complete with ≤5% contamination. In most samples, specialized microbial communities were established, while only a few taxa were widespread among the different reactor systems. Metabolic reconstruction of the MAGs enabled the prediction of functional traits related to biomass degradation and methane production from waste biomass. An extensive evaluation of the replication index provided an estimation of the growth rate for microbes involved in different steps of the food chain. The recovery of many MAGs belonging to Candidate Phyla Radiation and other underexplored taxa suggests their specific involvement in the anaerobic degradation of organic matter. Conclusions The outcome of this study highlights a high flexibility of the biogas microbiome, allowing it to modify its composition and to adapt to the environmental conditions, including temperatures and a wide range of substrates. Our findings enhance our mechanistic understanding of the AD microbiome and substantially extend the existing repository of genomes. The established database represents a relevant resource for future studies related to this engineered ecosystem. Keywords Anaerobic digestion, Metagenome-Assembled Genomes, Biogas, Microbial community structure, Functional reconstruction

scholarly journals Temperature Influences Nitrogen Release Rates in Cranberry Soils

HortScience ◽  
2004 ◽  
Vol 39 (1) ◽  
pp. 80-83 ◽  
Author(s):  
Joan R. Davenport ◽  
Carolyn DeMoranville
Keyword(s):  
Organic Matter ◽  
Soil Ph ◽  
Organic Matter Content ◽  
Matter Content ◽  
Organic Soils ◽  
Soil N ◽  
Wide Range ◽  
N Release ◽  
Different Temperatures ◽  
Soil Temperatures

Native nitrogen is released when soils are mineralized. The amount of N released by this process depends on the amount of organic matter present and soil temperature. Cranberry (Vaccinium macrocarpon Ait.) grows in acidic soils with a wide range in organic matter content. To evaluate release of cranberry soil N at varied soil temperatures, intact soils were collected from sites that had received no fertilizer. Soils were cored and placed in polyvinyl chloride (PVC) columns 20 cm deep × 5 cm in diameter. Four different soil types, representing the array of conditions in cranberry soil (mineral, sanded organic, organic peat, and muck) were used. Additional columns of sand soil (pH 4.5) that had been pH adjusted to high (6.5) and low (3.0) were also prepared. Each column was incubated sequentially at six different temperatures from 10 to 24 °C (2.8 °C temperature intervals) for 3 weeks at each temperature, with the soils leached twice weekly to determine the amount of N release. The total amount of N in leachate was highest in the organic soils, intermediate in the sanded organic, and lowest in the sands. At the lowest temperature (10 °C), higher amounts of N were released in sanded organic and sand than in organic soils. This was attributed to a flush of mineralization with change in the aerobic status and initial soil warming. The degree of decomposition in the organic soils was important in determining which form of N predominated in the leachate. In the more highly decomposed soil (muck), most of the N was converted to nitrate. In the pH adjusted sand, high soil pH (6.5) resulted in an increase in nitrate in the leachate but no change in ammonium when compared to non-adjusted (pH 4.5) and acidified (pH 3.0) treatments. This study suggests that for cranberry soils with organic matter content of at least 1.5% little to no soil-applied fertilizer N is needed early in the season, until soil temperatures reach 13 °C. This temperature is consistent with the beginning of active nutrient uptake by roots. Soil N release from native organic matter was fairly consistent until soil temperatures exceeded 21 °C, indicating that when temperatures exceed 21 °C, planned fertilizer applications should be reduced, particularly in highly organic soils.

Features of radiothermoluminescence of polypropylene and ethylene propylenediene elastomer SKEPT-4044 compositions with nanoscale metal-containing fillers

2020 ◽  
pp. 66-73
Author(s):  
A.M. Magerramov ◽  
◽  
N.I. Kurbanova ◽  
M.N. Bayramov ◽  
N.A. Alimirzoyeva ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Molecular Mobility ◽  
Fe3o4 Nanoparticles ◽  
Low Temperatures ◽  
Frost Resistance ◽  
Relaxation Processes ◽  
Ethylene Propylene ◽  
Temperature Range ◽  
Β Relaxation

Using radiothermoluminescence (RTL), the molecular mobility features in the temperature range of 77-300 K were studied for the polypropylene (PP)/ethylene propylene diene elastomer SKEPT-4044 with NiO, Cu2O and Fe3O4 nanoparticles (NPs) based on ABS-acrylonitrile butadiene or SCS-divinyl styrene matrices. It has been shown that the introduction of nanofillers in PP significantly affects the nature and temperature of γ- and β-relaxation processes, while the region of manifestation of the β-process noticeably shifts to the region of low temperatures. Composites with Cu2O NPs have a higher β-transition temperature Tβ than composites with other NPs. It was found that PP/SKEPT-4044 composites with Cu2O NPs with a dispersion of 11-15 nm and acrylonitrile butadiene thermoplastics have optimal frost resistance compared to other compositions.

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