scholarly journals Petroleum Pollution Bioremediation Using Water-Insoluble Uric Acid as the Nitrogen Source

2003 ◽  
Vol 69 (10) ◽  
pp. 6337-6339 ◽  
Author(s):  
Omry Koren ◽  
Vishnia Knezevic ◽  
Eliora Z. Ron ◽  
Eugene Rosenberg
Keyword(s):  
Uric Acid ◽  
Crude Oil ◽  
Nitrogen Source ◽  
Bacterial Growth ◽  
Open System ◽  
Open Systems ◽  
Petroleum Pollution ◽  
Acid Media ◽  
Enrichment Cultures ◽  
Pure Cultures

ABSTRACT The biodegradation of hydrocarbon pollutants in open systems is limited by the availability of a utilizable nitrogen source. This limitation can be overcome by using uric acid. Enrichment cultures grown on crude oil-uric acid media yielded mixed and pure cultures that degraded petroleum. In a simulated open system, uric acid bound to crude oil and was available for bacterial growth and petroleum biodegradation.

THE QUANTUM TRAJECTORY APPROACH TO GEOMETRIC PHASE FOR OPEN SYSTEMS

2005 ◽  
Vol 20 (22) ◽  
pp. 1635-1654 ◽  
Author(s):  
ANGELO CAROLLO
Keyword(s):  
Quantum System ◽  
Open System ◽  
Geometric Phase ◽  
Open Systems ◽  
Quantum Trajectory ◽  
Operational Method ◽  
Markovian Approximation ◽  
Physical Systems ◽  
Quantum Jump ◽  
Trajectory Approach

The quantum jump method for the calculation of geometric phase is reviewed. This is an operational method to associate a geometric phase to the evolution of a quantum system subjected to decoherence in an open system. The method is general and can be applied to many different physical systems, within the Markovian approximation. As examples, two main source of decoherence are considered: dephasing and spontaneous decay. It is shown that the geometric phase is to very large extent insensitive to the former, i.e. it is independent of the number of jumps determined by the dephasing operator.

Aspects of the weak-coupling theory of open systems

1983 ◽  
Vol 61 (11) ◽  
pp. 1479-1485 ◽  
Author(s):  
I. D. Cox ◽  
W. E. Hagston ◽  
B. J. Holmes
Keyword(s):  
Perturbation Theory ◽  
Open System ◽  
Weak Coupling ◽  
Open Systems ◽  
Higher Order ◽  
Projection Operators ◽  
Coupling Theory ◽  
Weak Coupling Theory ◽  
Damping Theory ◽  
Insight Into

Damping theory of an open system S is usually formulated in terms of projection operators which introduce nonuniqueness into the analysis. An insight into the nature of the approximations that arise from this aspect of the formalism is revealed by considering systems of varying complexity. This leads to the conclusion that the results of higher order perturbation theory approximations may not be meaningful.

scholarly journals Molecular Basis of a Bacterial Consortium: Interspecies Catabolism of Atrazine

1998 ◽  
Vol 64 (1) ◽  
pp. 178-184 ◽  
Author(s):  
Mervyn L. de Souza ◽  
David Newcombe ◽  
Sam Alvey ◽  
David E. Crowley ◽  
Anthony Hay ◽  
...  
Keyword(s):  
Nitrogen Source ◽  
Southern Hybridization ◽  
Cyanuric Acid ◽  
Bacterial Species ◽  
Bacterial Consortium ◽  
Triazine Ring ◽  
Carbon And Nitrogen ◽  
Consortium Member ◽  
Ring Compounds ◽  
Pure Cultures

ABSTRACT Pseudomonas sp. strain ADP contains the genes,atzA, -B, and -C, that encode three enzymes which metabolize atrazine to cyanuric acid. Atrazine-catabolizing pure cultures isolated from around the world contain genes homologous to atzA, -B, and -C. The present study was conducted to determine whether the same genes are present in an atrazine-catabolizing bacterial consortium and how the genes and metabolism are subdivided among member species. The consortium contained four or more bacterial species, but two members, Clavibacter michiganese ATZ1 andPseudomonas sp. strain CN1, collectively mineralized atrazine. C. michiganese ATZ1 released chloride from atrazine, produced hydroxyatrazine, and contained a homolog to theatzA gene that encoded atrazine chlorohydrolase. C. michiganese ATZ1 stoichiometrically metabolized hydroxyatrazine to N-ethylammelide and contained genes homologous toatzB and atzC, suggesting that either a functional AtzB or -C catalyzed N-isopropylamine release from hydroxyatrazine. C. michiganese ATZ1 grew on isopropylamine as its sole carbon and nitrogen source, explaining the ability of the consortium to use atrazine as the sole carbon and nitrogen source. A second consortium member, Pseudomonassp. strain CN1, metabolized the N-ethylammelide produced byC. michiganese ATZ1 to transiently form cyanuric acid, a reaction catalyzed by AtzC. A gene homologous to the atzCgene of Pseudomonas sp. strain ADP was present, as demonstrated by Southern hybridization and PCR. Pseudomonassp. strain CN1, but not C. michiganese, metabolized cyanuric acid. The consortium metabolized atrazine faster than didC. michiganese individually. Additionally, the consortium metabolized a much broader set of triazine ring compounds than did previously described pure cultures in which the atzABCgenes had been identified. These data begin to elucidate the genetic and metabolic bases of catabolism by multimember consortia.

A modification of the method using cellulose overlay agar to isolate and purify cellulolytic cytophagas from enrichment culture

1992 ◽  
Vol 38 (7) ◽  
pp. 687-689 ◽  
Author(s):  
R. A. Drijber ◽  
W. B. McGill
Keyword(s):  
Key Words ◽  
Enrichment Culture ◽  
Soil Samples ◽  
Existing Problems ◽  
Enrichment Cultures ◽  
Pure Cultures ◽  
Back Door ◽  
Agar Surface ◽  
Agar Method

We report here on a modification of the cellulose overlay agar method for isolating and purifying cellulolytic cytophagas from enrichment cultures. We call it the "back-door" method, and it overcomes two existing problems. First, it prevents recontamination with organisms growing on the agar surface. Second, it permits purification of cellulolytic cytophagas that are unable to utilize glucose or that are accompanied by a rapidly growing contaminant with spreading habit. Pure cultures of cellulolytic cytophagas were obtained from five enrichment cultures of nine soil samples examined. Two limitations are that (i) the cytophaga must be able to penetrate the overlay and (ii) some noncellulolytic cytophagas may also penetrate the overlay to yield cocultures. In conclusion, the back-door method can be used both to isolate and purify cellulolytic cytophagas from soils, using only a cellulose-based medium. Key words: back-door method, cellulolytic cytophagas, cellulose overlay agar, cellulolysis.

Average radial growth rate and chlamydospore production of Ceratocystis minor, Ceratocystis minor var. barrasii, and SJB 122 in culture

1989 ◽  
Vol 67 (12) ◽  
pp. 3498-3505 ◽  
Author(s):  
David S. Goldhammer ◽  
Frederick M. Stephen ◽  
Timothy D. Paine
Keyword(s):  
Growth Rate ◽  
Uric Acid ◽  
Loblolly Pine ◽  
Radial Growth ◽  
Dendroctonus Frontalis ◽  
Radial Growth Rate ◽  
Acid Media ◽  
Low Concentrations ◽  
Pinus Taeda L ◽  
Ceratocystis Minor

Two symbiotic fungi (SJB 122, an unidentified basidiomycete, and Ceratocystis minor (Hedgecock) Hunt variety barrasii Taylor) and one pathogenic phoretic fungus (C. minor (Hedgecock) Hunt variety minor) of the southern pine beetle, Dendroctonus frontalis Zimmermann, were inoculated onto six different concentrations of D. frontalis frass, loblolly pine (Pinus taeda L.) phloem, and uric acid media to observe radial growth rates and chlamydospore production. The average radial growth rate per day of C. minor var. barrasii increased significantly from the control on all three media, but growth was faster at increased concentrations of added phloem compared with the other supplemented media. Significant increases in chlamydospores produced by C. minor var. barrasii from the control occurred only on frass media, with more chlamydospores being produced at higher concentrations. The average radial growth rate per day of SJB 122 fungus increased significantly from the control on only one concentration of phloem and two concentrations of uric acid, but decreased significantly on low concentrations of frass media. SJB 122 chlamydospore production increased with increasing concentration on frass, was not different from the control on phloem, and increased significantly at intermediate concentrations on uric acid. Ceratocystis minor var. minor average radial growth rate per day increased with increasing concentration on both frass and phloem media but on uric acid decreased significantly at higher concentrations, following an initial signficant increase as compared with the controls.

Protein Metabolism in Trematode Parasites

1958 ◽  
Vol 32 (3) ◽  
pp. 119-124 ◽  
Author(s):  
M. M. Goil
Keyword(s):  
Uric Acid ◽  
Bacterial Growth ◽  
Protein Metabolism ◽  
Nutrient Medium ◽  
Dry Weight ◽  
Fasciola Gigantica ◽  
Starvation Period ◽  
Gastrothylax Crumenifer ◽  
Suitable Temperature ◽  
Trematode Parasites

Paramphistomum explanation, Gastrothylax crumenifer, and Fasciola gigantica were maintained for periods of twelve hours in a non-nutrient medium containing streptomycin and penicillin to prevent bacterial growth. They were kept under aerobic conditions at a suitable temperature of 37%C. The protein content in P. explanatum ranged from 50·0% to 54·7% with an average of 52·96%±0·23 of the dry weight of the tissue. In G. crumenifer it ranged from 43·5% to 51·5% with an average of 48·8%±0·56 of d.w.t. In F. gigantica it ranged from 63·8% to 68·3% with an average of 66·5%±0·26 of d.w.t. The nitrogen content of the P. explanation excreted as ammonia after a starvation period of twelve hours was 3·95% and as uric acid it was 0·077%. In G. crumenifer the ammonia was 2·91% and uric acid 0·033%. In F. gigantica ammonia was 2·51% and uric acid 0·1%.

E-Cigarettes: Policy Options and Legal Issues Amidst Uncertainty

2015 ◽  
Vol 43 (S1) ◽  
pp. 23-26 ◽  
Author(s):  
Nancy Kaufman ◽  
Margaret Mahoney
Keyword(s):  
Smoking Cessation ◽  
Propylene Glycol ◽  
Open System ◽  
Closed System ◽  
Open Systems ◽  
Delivery Systems ◽  
Legal Issues ◽  
Policy Options ◽  
Electronic Nicotine Delivery Systems ◽  
Closed Systems

E-cigarettes, sometimes referred to as ENDS (Electronic Nicotine Delivery Systems), include a broad range of products that deliver nicotine via heating and aerosolization of the drug. ENDS come in a variety of forms, but regardless of form generally consist of a solution containing humectant (e.g., propylene glycol or glycerol), flavorings, and usually nicotine (some solutions do not contain nicotine); a battery-powered coil that heats the solution into an aerosol (usually referred to as vapor) in an atomizing chamber; and a mouthpiece through which the user draws the vapor into the mouth and lungs. The devices may be closed systems containing prefilled cartridges, or open systems, where the user manually refills a 1-2 ml. tank with solution. What started as closed-system cigarette-shaped devices marketed as an adjunct for smoking cessation, has transitioned rapidly to literally thousands of hip and funky-designed open-system hookah pens, vape pens, and modifiable devices. For younger people, these forms are the “in” thing, while traditional cigarette-shaped devices are “out.”

scholarly journals Kinetics of substrate utilization and bacterial growth of crude oil degraded by Pseudomonas aeruginosa

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Amirreza Talaiekhozani ◽  
Nematollah Jafarzadeh ◽  
Mohamad Ali Fulazzaky ◽  
Mohammad Reza Talaie ◽  
Masoud Beheshti
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Crude Oil ◽  
Bacterial Growth ◽  
Substrate Utilization ◽  
Kinetics Of

Uric acid utilization inPlatymonas convolutaeand symbioticConvoluta roscoffensis

1983 ◽  
Vol 63 (2) ◽  
pp. 435-447 ◽  
Author(s):  
A. E. Douglas
Keyword(s):  
Uric Acid ◽  
Nitrogen Source ◽  
Culture Conditions ◽  
Acid Uptake ◽  
Intact Cells ◽  
Algal Symbionts ◽  
Standard Culture ◽  
System Operating ◽  
Nitrogen Demand ◽  
Convoluta Roscoffensis

Uric acid is an excellent nitrogen source for the growth of cultures ofPlatymonas convolutae, the symbiotic alga fromConvoluta roscoffensis, and relatedPlatymonasandTetraselmisspecies. Nitrate-grown cells ofP. convolutaeandT. tetrathelehave two uptake systems for uric acid, which conform to Michaelis–Menten kinetics; a high-affinity system operating in the concentration range 0·2–4·5 μM a nd a low-affinity system operating at higher concentrations of uric acid. Uric acid uptake byP. convolutaeis abolished by uncouplers of phosphorylation. In darkness, intact cells ofP. convolutaemetabolize [2-14C]uric acid to [14C]carbon dioxide. These results are consistent with the proposal that the algal symbionts ofC. roscoffensisutilize uric acid, received from the host, as a nitrogen source.Aposymbiotic juvenile and symbiotic adultC. roscoffensisunder standard culture conditions contain uric acid. The solid uric acid content of juveniles declines on establishment of symbiosis withP. convolutaeand the endogenous uric acid is utilized in the adult symbiosis under conditions of nitrogen demand. However, adultC. roscoffensisdo not utilize exogenous uric acid. The growth of adult but not juvenileC. roscoffensisis dependent on nitrogen enrichment of the medium, and it is proposed that uric acid utilization is of significance to the growth of the developing symbiosis in a nitrogen-poor environment.

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