Insights Gained from the Dehalococcoides ethenogenes" Strain 195's Transcriptome Responding to a Wide Range of Respiration Rates and Substrate Types"

2012 ◽  
Author(s):  
Cresten Manfeldt ◽  
Annette Rowe ◽  
Gretchen Heavner ◽  
Stephen Zinder ◽  
Ruth Richardson
Keyword(s):  
Respiration Rates ◽  
Dehalococcoides Ethenogenes ◽  
Wide Range ◽  
Substrate Types

Rapid reduction of nitrate in soil re-moistened after air-drying

1972 ◽  
Vol 78 (3) ◽  
pp. 405-412 ◽  
Author(s):  
P. A. Cawse ◽  
D. Sheldon
Keyword(s):  
Nitrous Oxide ◽  
Calcareous Soil ◽  
Calcareous Soils ◽  
Soil Nitrate ◽  
Nitrite Concentration ◽  
Rapid Reduction ◽  
Air Drying ◽  
Moisture Contents ◽  
Respiration Rates ◽  
Wide Range

SUMMARYWhen an organic calcareous soil was air-dried for 2 days and re-wetted to a wide range of moisture contents, well below saturation, nitrite accumulated within 1–2 days. At the same time much nitrate was formed and more carbon dioxide was released than from soil kept moist. On further incubation of re-wetted soil for 3–5 days, the nitrite concentration decreased rapidly. Since 15N-labelled nitrate was reduced to nitrite after air-drying and re-wetting, and no nitrite was formed in autoclaved soil, nitrate was microbially reduced.Eighty-three per cent of added 15N tracer was recovered from the soil 2 days after re-wetting to 70 % moisture, indicating that 58 ppm N had been lost; 10 ppm N of this was released as nitrous oxide. Autoclaved soil to which nitrite was added did not evolve nitrous oxide, suggesting that nitrite was reduced biologically rather than decomposed chemically.Three other soils were treated similarly; two, which were non-calcareous, accumulated no nitrite. Fresh calcareous soils with high respiration rates and good capacities to denitrify when waterlogged are most likely to form nitrite after drying and moderate re-wetting.

scholarly journals Temporal Transcriptomic Microarray Analysis of “Dehalococcoides ethenogenes” Strain 195 during the Transition into Stationary Phase

2008 ◽  
Vol 74 (9) ◽  
pp. 2864-2872 ◽  
Author(s):  
David R. Johnson ◽  
Eoin L. Brodie ◽  
Alan E. Hubbard ◽  
Gary L. Andersen ◽  
Stephen H. Zinder ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Dna Microarrays ◽  
Molecular Evidence ◽  
Unexpected Finding ◽  
Dynamic Changes ◽  
General Stress Response ◽  
Dehalococcoides Ethenogenes ◽  
Wide Range ◽  
Number Of Genes ◽  
Genes Encoding

ABSTRACT “Dehalococcoides” bacteria can reductively dehalogenate a wide range of halogenated organic pollutants. In this study, DNA microarrays were used to monitor dynamic changes in the transcriptome as “Dehalococcoides ethenogenes” strain 195 transitioned from exponential growth into stationary phase. In total, 415 nonredundant genes were identified as differentially expressed. As expected, genes involved with translation and energy metabolism were down-regulated while genes involved with general stress response, transcription, and signal transduction were up-regulated. Unexpected, however, was the 8- to 10-fold up-regulation of four putative reductive dehalogenases (RDases) (DET0173, DET0180, DET1535, and DET1545). Another unexpected finding was the up-regulation of a large number of genes located within integrated elements, including a putative prophage and a multicopy transposon. Finally, genes encoding the dominant hydrogenase-RDase respiratory chain of this strain (Hup and TceA) were expressed at stable levels throughout the experiment, providing molecular evidence that strain 195 can uncouple dechlorination from net growth.

scholarly journals Respiration rates of herring larvae at different salinities, and effects of previous environmental history

2020 ◽  
Vol 650 ◽  
pp. 141-152 ◽  
Author(s):  
F Berg ◽  
L Andersson ◽  
A Folkvord
Keyword(s):  
Environmental History ◽  
Fish Larvae ◽  
Early Life History ◽  
Clupea Harengus ◽  
Metabolic Rates ◽  
Contributing Factors ◽  
Extrinsic Factors ◽  
Respiration Rates ◽  
The North ◽  
Wide Range

Metabolic rates of early life history stages of marine fishes show considerable inter-individual differences, and are highly influenced by extrinsic factors like temperature or food availability. Measuring oxygen uptake rates is a proxy for estimating metabolic rates. Still, the relationship between respiration rates and ambient or previous salinity conditions as well as parental and developmental acclimation to changes in salinity remains largely unexplored. In the present study, we conducted experiments to investigate the effects of salinity on the routine metabolic rates (RMR) of euryhaline Atlantic herring Clupea harengus larvae at 3 levels of salinity: low (6 psu), intermediate (16 psu) and high (35 psu), reflecting ecologically relevant conditions for herring populations in the Atlantic Ocean and Baltic Sea. The larvae originated from different genetic backgrounds and salinity adaptations to account for cross-generation effects on metabolic rates. Closed respirometry carried out over 24 h on individual fish larvae generally confirmed near isometric respiration rates at all salinity regimes, with rates being 15.4% higher at 6 psu and 7.5% higher at 35 psu compared to 16 psu conditions. However, transgenerational acclimation to different salinity regimes of the parents had no effect on the salinity-specific metabolic rates of their offspring. Our study demonstrates the ability of herring to cope with a wide range of salinity conditions, irrespective of parental environmental history and genetic origin. This phenotypic plasticity is considered to be one of the main contributing factors to the success of herring as a widely distributed fish species in the North Atlantic and adjacent waters.

THE INTERACTIVE EFFECTS OF TEMPERATURE, SALINITY, AND SUBLETHAL EXPOSURE TO PHENANTHRENE, A PETROLEUM-DERIVED POLYCYCLIC AROMATIC HYDROCARBON (PAH), ON THE RESPIRATION RATE OF JUVENILE MUD CRABS, RHITHROPANOPEUS HARRISII

1979 ◽  
Vol 1979 (1) ◽  
pp. 585-590
Author(s):  
Roy B. Laughlin ◽  
J. M. Neff
Keyword(s):  
Respiration Rate ◽  
Osmotic Shock ◽  
Specific Pattern ◽  
Interactive Effects ◽  
Rhithropanopeus Harrisii ◽  
Respiration Rates ◽  
Wide Range ◽  
Polycyclic Aromatic ◽  
Physical Environmental Factors ◽  
Mud Crabs

ABSTRACT Laboratory-reared juvenile mud crabs; Rhithropanopeus harrisii, were acclimated to temperature-salinity combinations of 20, 25, or 30°C and 5, 15, or 25 parts per thousand (‰) salinity. Subsequently, they were exposed for 10 days to phenanthrene concentrations of 0, 75, 150, or 300 µg/l (ppb). This gave a complete 3 × 3 × 4 factorial design of the factor combinations. On the tenth day of phenanthrene exposure the respiration rates of the crabs were determined both at steady state with the rearing salinity, and immediately following a move from either 15 ‰ to 5 ‰ salinity (hypoosmotic shock) or 15 ‰ to 25 ‰ salinity (hyperosmotic shock). To a certain extent, all the factors tested affected the respiration rates. An increase in temperature usually caused an increase in the respiration rate, although this was small. The juvenile crabs were tolerant both to a wide range of acclimation salinities, and to osmotic shock under control conditions. However, phenanthrene-exposed animals showed marked changes in respiration rates compared to controls. In most cases, mean respiration rates of phenanthrene-exposed juveniles increased over control rates. However, the specific pattern was largely a function of all three variables tested. The percent body water of phenanthrene-exposed crabs tended to be higher than that of the controls. This may indicate that the phenanthrene-exposed animals had difficulty osmoregulating. The results of this study show that physical environmental factors such as temperature and salinity influence the nature and magnitude of the sublethal physiological response of an estuarine invertebrate to hydrocarbon pollution.

scholarly journals Habitat Requirements and Selection by Kelp Gulls (Larus Dominicanus) in Central and Northern Patagonia, Argentina

The Auk ◽  
2004 ◽  
Vol 121 (1) ◽  
pp. 243-252
Author(s):  
Pablo García Borboroglu ◽  
Pablo Yorio
Keyword(s):  
Vegetation Cover ◽  
Positive Association ◽  
Habitat Requirements ◽  
Northern Patagonia ◽  
Larus Dominicanus ◽  
Wide Range ◽  
Open Ground ◽  
Olrog’S Gull ◽  
Substrate Types ◽  
Selection Of

Abstract We analyzed habitat requirements and selection of Kelp Gulls (Larus dominicanus) breeding at 68 colonies along 2,500 km of coastline in Patagonia, Argentina. Kelp Gulls use a wide range of nesting habitats that include areas with shrub, grass, and herbs which provide different degrees of cover; open ground of various substrate types; and slopes of widely different gradients, confirming the plasticity of the species with respect to habitat recorded elsewhere in the Southern Hemisphere. Eighty percent of the colonies were on islands, the probability of occupation of which increased with distance from mainland and availability of vegetation. Vegetation cover was a key component of nesting habitat for Kelp Gulls in Argentina. Gulls occupied areas with higher cover than random areas; but within vegetated areas, they showed preference for sparser cover that increased visibility and facilitated escape. Kelp Gulls often nested with other species of seabirds and seals and had a positive association with the Olrog's Gull (L. atlanticus).

THE INFLUENCE OF SOIL MOISTURE ON UREA HYDROLYSIS AND MICROBIAL RESPIRATION IN JACK PINE HUMUS

1980 ◽  
Vol 60 (4) ◽  
pp. 675-684 ◽  
Author(s):  
N. W. FOSTER ◽  
E. G. BEAUCHAMP ◽  
C. T. CORKE
Keyword(s):  
Soil Moisture ◽  
Pinus Banksiana ◽  
Microbial Respiration ◽  
Jack Pine ◽  
Urea Hydrolysis ◽  
Moist Soil ◽  
Respiration Rates ◽  
Microbial Response ◽  
Incubation Study ◽  
Wide Range

The influence of soil moisture on urea hydrolysis and microbial respiration in mixed L and F horizons of a Brunisolic soil under a boreal forest jack pine (Pinus banksiana Lamb.) stand was determined in an incubation study at 13 °C. Respiration rates in untreated soil were similar over a wide range of moisture contents below 300% (45% water-holding capacity). Significant decreases in respiration rates occurred only below 60% moisture content. Initial microbial response to urea increased as soil moisture rose from 20 to 300%. There was sufficient urease in pine humus to hydrolyze rapidly the equivalent of 200 kg urea-N∙ha−1, when moisture was not limiting. During the drying of initially moist soil (340% H2O) to 240% H2O or lower, urea hydrolysis was retarded significantly and microbial respiration reduced by an average of 25% over that observed in a constantly moist soil.

Interesting anaerobes in the environment

2015 ◽  
Vol 36 (3) ◽  
pp. 133
Author(s):  
Linda L Blackall
Keyword(s):  
Iron Reduction ◽  
Paracoccus Denitrificans ◽  
Anaerobic Respiration ◽  
Oxygen Radical ◽  
Ammonium Oxidation ◽  
Dehalococcoides Ethenogenes ◽  
Wide Range ◽  
Metabolic Strategies ◽  
Iron Manganese ◽  
Lactobacillus Spp

Prokaryotes (Bacteria and Archaea) have a wide range of capacities to survive by generating energy in environments and situations lacking oxygen, which abound on Earth. Anaerobic metabolic strategies include anaerobic respiration (numerous types – e.g. nitrate reduction – Paracoccus denitrificans; sulfur respiration – Desulfuromonadales; methanogenesis – Methanosarsina spp.; iron reduction – Geobacter spp.; dehalorespiration – Dehalococcoides ethenogenes) and fermentation (sugars converted to simpler organic compounds like acids, gases and alcohols – e.g. Lactobacillus spp.). Relatively novel environmental anaerobic strategies include anaerobic ammonium oxidation (Anammox – e.g. Brocadia spp.) and anaerobic methane oxidation (AMO)1, which is a syntrophic association between anaerobic methanotrophic archaea (ANME) and sulfate-, iron-, manganese- or nitrate-reducing bacteria2. The classic anaerobic synthrophic example is interspecies hydrogen/formate transfer between a hydrogen/formate producing fatty acid oxidising bacterium (the syntroph) and a hydrogen/formate consumer (methanogen or sulfate-reducer)3. Microbes vary in their oxygen tolerance and are described as obligate anaerobes if they are killed by atmospheric levels of oxygen due to the lack of catalase and superoxide dismutase that provide oxygen radical protection.

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

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