Bei all dem wird nicht vergessen, dass Sport und Bewegung neben dem Korper auch der Seele gut tun. Erstmalig wird hier mit einer ausgefeilten experimentellen Untersuchungseinrichtung Grundlagenwissen zur Funktion des Kniebandapparats, zu seinen Verletzungen und seiner Wiederherstellung erarbeitet. Neue Ergebnisse lassen sich insbesondere aus der Muskelsimulationsuntersuchung gewinnen: Die gewonnenen Ergebnisse werden vergleichend mit der modernen Literatur umfassend diskutiert. Thema dieser Tagung war die funktionelle Begleit- und Nachbehandlung nach operativ versorgten Kapsel-Band-Verletzungen des Kniegelenkes.
Neben funktioneller Anatomie und Biomechanik werden die Ergebnisse tierexperimenteller Studien zum Einheilungsverhalten nach plastischem Kreuzbandersatz vorgestellt und Grundlagen der funktionellen Begleit- und Nachbehandlung demonstriert.
Von besonderem Interesse sind in diesem Zusammenhang unterschiedliche Therapiekonzepte aus fuhrenden Zentren sowie Moglichkeiten flankierender Massnahmen, wie Isokinetik und Elektrostimulation. Schliesslich werden physiologische und praktische Erfahrungen aus der Sicht der Sportwissenschaft, des Physiotherapeuten und des Hochleistungssportlers dargestellt und durch die modernen Grundlagen orthopadietechnischer Versorgung erganzt. Die Folge sind ein verminderter Ostrogenspiegel und eine gestorte Entwicklung des im adoleszenten Alter notwendigen Knochenaufbaus.
Bei den betroffenen Athletinnen kommt es gehauft zu Ermudungsbruchen der unteren Extremitaten, als deren Ursache neben biomedizinischen Faktoren die verminderte Knochendichte angesehen werden kann. Bisher wurde die Stressfraktur als rein orthopadisches Problem angesehen. In diesem Buch wird das Thema zum ersten Mal interdisziplinar diskutiert von Wissenschaftlern aus den Gebieten der internistischen Osteologie, gynakologischen Endokrinologie, diagnostischen Radiologie, Orthopadie und Ernahrungswissenschaft. Erfahrungen aus der Trainingslehre, der Sportphysiotherapie und von betroffenen Athletinnen runden die Darstellung ab.
In diesem Band werden umfassend die anatomischen und biomechanischen Grundlagen, die Moglichkeiten und Grenzen der geschlossenen und die Indikation und Technik der offenen Repositionstechnik des gesamten Skelettsystems dargestellt. Bewahrte Repositionstechniken sowie Tricks und Tips aus der Praxis bei schwierigen Repositionen, werden detailliert und anschaulich beschrieben. Der Band vermittelt ein aktuelles, praktisch erprobtes Konzept zur Wahl und Durchfuhrung der geeigneten Repositionsmethode fur jeden, der mit Frakturen und Luxationen aller Art konfrontiert wird.
Steinacker; Edited by Jurgen M. Steinacker; Contributions by W. Die vielfaltigen Probleme des Frauensports zusammen mit den aktuellen Ergebnissen der wissenschaftlichen Forschung werden in diesem Buch erstmalig zusammen dargestellt. Rost; Translated by Richard Rost, G. Trotzdem steht zur klinischen Anwendung nur wenig von diesem Wissen in den Standardlehrbuchern der Kinderheilkun de zur Verfiigung. Das vorliegende Buch soli die hier entstandene Lucke schlieBen. Bis in die Mitte der 60er Jahre konzentrierte sich die sportmedizinische Forschung auf den jungen Erwachsenen bzw.
In den letzten Jahren laBt sich dagegen ein zunehmen des Interesse des Leistungsphysiologen gerade am Kind und am Jugendli chen beobachten. Ein wichtiger AnstoB fiir dieses Interesse war die wach sende Einbeziehung von Kindern in den leistungssportlichen Bereich. Heute sehen sich Kinder und jugendliche Leistungssportler hiiufig Trai ningsbedingungen ausgesetzt, die noch vor 10 Jahren keinem erwachsenen Athleten zugemutet worden waren. In anderen Sportarten, wie beispielsweise Ten nis, wird der Leistungsgipfel nach wie vor erst in der dritten Lebensdeka de erreicht, aber ein systematisches Training, das bereits in der Kindheit beginnt, ist auch hier obligatorisch.
Die wachsende Popularitat des Jog gings und anderer sportlicher Freizeitaktivitaten zieht Menschen aller Al tersstufen an. Noch vor wenigen Jahren wurde der Langlauf fiir Kinder vollig abgelehnt. Wenn heutzutage ein 10 Jahre altes Kind ein Marathon rennen zu Ende lauft, so erregt dies kaum noch Aufsehen. Verlust der Gesundheit und viele Krankheiten sind in der technisierten Zivilisation unserer Zeit haufige Folge von Mangel an k6rperlicher Arbeit oder sportlichem Training.
Alle Fort schritte der modernen Medizin haben die Zunahme vieler Krankheiten unserer Zeit und eine immense Kostenzunahme im Krankheitswesen nicht verhindern k6nnen. Die kurative Medizin ist in zunehmendem MaB iiberfordert. In dieser Situation kommt es darauf an, Ursachen und Bedingungen der Pathogenese, des Krankwerdens, besser zu erkennen - und durch praventive MaBnahmen zu beheben.
Arztevereinigungen, Gesundheitsamter, Krankenkassen und politische Parteien stimmen iiberein in der Auffassung: Training und sportliche Aktivitaten bestimmter Qualitat und Quantitat geh6ren in unserer Zeit zu den wirksamsten Methoden der praventiven und rehabilitiven Medizin. Hierzu ist in den letzten Jahrzehnten ein reiches und wohlfundiertes Forschungs-und Erfahrungsgut zusammengetragen worden. Es bedarf jetzt der wei ten Anwendung durch alle, insbesonde re durch Arzte, die nicht nur Krankheiten heilen, sondern Gesundheit erhalten und f6rdern wollen, durch Sportlehrer, die Leibes-und Gesundheitserzieher in den Schulen fiir jeden jungen Menschen sein sollen und wollen.
In der Bundesrepublik sind heute tiber und in der Schweiz tiber Manner und Frauen in Un terwassersportvereinen organisiert. Mit der Gewinnung von Minera lien, Erdol usw. Hierftir werden Menschen benotigt, die tagelang unter Wasser oder in Unterwasserhausem Oberdruckkammem leben.
Ich bin Neukunde
Aber auch Archaologen, Zoologen, Geologen, Hohlenforscher usw. Die Militars traumen seit dem Altertum von Unterwasserkampfem, aber erst seit dem zweiten Weltkrieg hat der Kampftaucher z. Es gibt verschiedene Moglichkeiten, urn in die Wassertiefe vorzu dringen. Diese Art des Tauchens, unter dem der Tiefe entsprechenden Uberdruck, fiihrte im vergangenen Jahrhundert zur Entwicklung der sogenannten "Caissons," mit deren Hilfe Unterwasserarbeiten im Trockenen ausge fiihrt werden konnen.
Athletic Trainers especially must understand how epidemiology shapes healthcare practices for physically active patients. To meet this need, Epidemiology for Athletic Trainers: Integrating Evidence-Based Practice is a succinct and comprehensive reference meant to develop and refine student and clinician evidence-based practice skills. This text addresses the prevalence, risk factors, and surveillance of sports-related injury and illness at youth, college, and professional levels. Inside Epidemiology for Athletic Trainers: Integrating Evidence-Based Practice, Drs. Wanda Swiger and Melanie M.
Adams guide the reader through the steps of evidence-based practice by presenting basic research and statistical methods needed to read medical literature. Key sport epidemiology studies are reviewed for both historical and clinical significance. This foundation is built on with a deeper discussion of injury and illness prevention and future research. Chapters cover a wide range of topics including the health benefits of physical activity, concussion return to play guidelines, ACL prevention, mental health concerns, and skin infections.
This text provides an exceptional approach to integrating evidence-based practice skills with clinical practice. Meets the Commission on Accreditation of Athletic Training Education CAATE outcomesIncludes classroom activities to make the text interactive and expand the student's or clinician's research skillsFosters the use of prevention practices and health promotion within athletic trainingInstructors in educational settings can visit www. Epidemiology for Athletic Trainers: Integrating Evidence-Based Practice is a must-have for any athletic training student or clinician looking to improve his or her decision-making skills within an evidence-based context.
The content is scientifically supported, practical, and suitably written for a range of audiences, including academics professors and students and sports and health professionals coaches, physical educators, nutritionists, and physicians , as well as athletes and individuals involved in physical activities. Compared to other books previously published in this area, this book does not limit body hydration issues to the average or elite adult athlete.
Rather, it addresses aspects relevant to a range of individuals of different ages adolescents and master athletes competing in various sports. In recognition of the growing number of individuals with specific medical conditions who have been exercising more and even participating in competitive sports, separate chapters on prevalent diseases or medical conditions associated with risks of body fluid homeostasis also are presented.
To achieve such a complete and qualified publication, the book is written by top experts and professionals experienced in their respective research areas.
It presents the basics of fluid balance and provides updates on controversial fluid intake-related issues such as hyponatremia, optimal recovery, intermittent sports, and perceptual responses. Are you seeking brief, up-to-date, expert advice for common issues that can be encountered when working with athletes? Quick Questions in the Shoulder: Expert Advice in Sports Medicine provides a unique format of concise and to the point responses with clinical application, backed by the latest research on shoulder injuries among athletes.
Huxel Bliven and her contributors present 39 common clinical questions regarding the prevention, assessment, treatment, management, and rehabilitation of the shoulder. Expert Advice in Sports Medicine provides concise answers to 39 frequently asked clinical questions. Written in a conversational tone, the authors of the individual questions represent a variety of different backgrounds and are experts in their respective field.
The variety of questions and brevity of responses will make this a book that is easy to read and reference at the point of care. Some sample sections and questions include: Factors related to shoulder functionHow does the trunk contribute to upper extremity function and injury risk in overhead athletes?
Injury diagnosisWhat are the best clinical tests for determining if a patient has scapular dyskinesis and to determine if it is contributing to their shoulder pain and dysfunction? Injury treatment and rehabilitationWhat are the most effective glenohumeral mobilization techniques and when are they most appropriate to use to improve shoulder function and range of motion? Kunden- und wettbewerbsorientierte Produktentwicklung mit QFD: I Frankrike har vi sett et marked som skiller seg en del fra det norske og tyske.
Enzymatisk omestring til produktion af biodiesel. Ved den industrielle fremstilling af Lean hos masskundanpassande producenter: Att masskundanpassa produkter effektivt. Denitrification by Rhizobium meliloti. Rhizobium meliloti strains were investigated for their denitrification activity as free-living cells and in nodules on lucerne Medicago sativa roots.
They were also investigated for presence of nitrous oxide reductase nos activity and for genes using a nosZ probe derived from the Pseudomonas stutzeri. To decide whether R. The nitrate reduction activity of R. A great diversity in the denitrification activity was found within strains of R. Two denitrifying bacteria were used as references, one strain each of Bradyrhizobium japonicum and P. All but one of the R. Two sizes of the hybridizing fragment, 5 and 7 kb, were noticed. Nos activity was only shown in three R.
The potential denitrification activity was about 20, 40, and 80 times higher than the actual denitrification activity for lucerne, fallow, and grass, respectively. The potential denitrification activity was almost the same in lucerne and grass planted soils. Compared with the unplanted soil, the presence of lucerne roots in the soil increased the actual denitrification activity, while roots of both plant species, grass and lucerne, increased the potential denitrification activity in the soil. Det er en stor udfordring at skabe det operationelle grundlag for en industriel produktion af mikro-teknologiske produkter.
Det er en stor udfordring at skabe det operationelle grundlag for en industriel produktion af mikro-teknologiske produkter Her er der tale om unikke produkter , hvor det i praksis udelukkende er landmanden og landmandens placering og produktion , som skaber de unikke In diesem Beitrag wird das Modul vorgestellt, dass die Prozessabbilder erstellt. Neben der Visualisierung von Anlagen werden auch laufende Prozesse und bearbeitete Produkte dargestellt.
Die exzessive Bildung und Ablagerung von aggregiertem Amyloid beta-Peptid im Gehirn von Alzheimer Patienten wird allgemein als zentrales Ereignis im Rahmen des Neurodegenerationsprozesses der Alzheimer Demenz betrachtet. Denitrification in the Arabian Sea. A method involving oxidative ratios has been modified and used to calculate nitrate deficits. The deficits so calculated lie between the values reported earlier Utilisation potential of products of microbial coal liquefaction. Final report; Verwertungspotential der Produkte der mikrobiellen Kohleverfluessigung.
Ever since the discovery in the s that microorganisms are capable of converting coal into soluble products research groups all over the world have been exploring the bioconversion of coal. It was at an advance stage of the present integrated project, which initially only involved microbiology research groups, that the need for a chemical working group with knowledge and experience in the area of coal chemistry and structural analysis of coal was recognised.
The task of the chemical working group was to provide knowledge on the chemical nature of bioconversion products and the chemical processes of coal bioconversion. This involved identifying structural changes occurring in the feed coal as well as in its constituent humic acids and macromolecular matrix as a result of the activity of coal degrading microorganisms. In einem fortgeschrittenen Bearbeitungsstadium des Verbundprojektes, an dem zunaechst nur mikrobiologische Arbeitsgruppen beteiligt waren, wurde die Notwendigkeit erkannt, eine chemische Arbeitsgruppe mit Kenntnissen und Erfahrungen auf den Gebieten der Kohlechemie und der Strukturanalytik von Kohlen zu integrieren.
Aufgabenstellung der chemischen Arbeitsgruppe war und ist es, Erkenntnisse ueber die chemische Natur der Biokonversionsprodukte und die chemischen Ablaeufe der mikrobiellen Kohlekonversion bereitstellen. Die Aufgabenstellung umfasst die Aufklaerung der strukturellen Veraenderung der Einsatzkohle sowie ihrer Komponenten Huminsaeuren und makromolekulare Matrix durch die Einwirkung kohleabbauender Mikroorganismen.
Denitrification in human dental plaque. Full Text Available Abstract Background Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate NO3- concentrations in the millimolar range and that dental plaque houses bacteria that can reduce this NO3- to nitrite NO Results We show that dental plaque mediates denitrification of NO3- to nitric oxide NO, nitrous oxide N2O, and dinitrogen N2 using microsensor measurements, 15N isotopic labelling and molecular detection of denitrification genes.
In vivo N2O accumulation rates in the mouth depended on the presence of dental plaque and on salivary NO3- concentrations. NO and N2O production by denitrification occurred under aerobic conditions and was regulated by plaque pH. Conclusions Increases of NO concentrations were in the range of effective concentrations for NO signalling to human host cells and, thus, may locally affect blood flow, signalling between nerves and inflammatory processes in the gum. This is specifically significant for the understanding of periodontal diseases, where NO has been shown to play a key role, but where gingival cells are believed to be the only source of NO.
More generally, this study establishes denitrification by human-associated microbial communities as a significant metabolic pathway which, due to concurrent NO formation, provides a basis for symbiotic interactions. Molecular Approaches to Studying Denitrification. Denitrification is carried out by a diverse array of microbes, mainly as an alternative mode of respiration that allows the organisms to respire using oxidized N compounds instead of oxygen. A common approach in biogeochemistry to the study of the regulation of denitrification is to assess activity by mass balance of substrates and products or direct rate measurements and has intrinsically assumed resource regulation of denitrification.
Reported rates can vary significantly even among ecosystems characterized by similar environmental conditions, thus indicating that direct control by abiotic factors often is not sufficient to predict denitrification rates accurately in natural environments. Alternatively, a microbiological approach would proceed with the identification of the organisms responsible and an evaluation of the effect of environmental factors on the biochemical pathways involved. Traditional studies have relied on culturing techniques, such as most probable number enrichments, and have failed to assess the role of the predominately uncultivable members of the microbial community.
A combination of biogeochemical measurements and the assessment of the microbial community is necessary and becoming increasingly possible with the development and application of molecular techniques. In order to understand how the composition and physiological behavior of the microbial community affects denitrification rates, we use a suite of molecular techniques developed for phylogenetic and metabolic characterization of denitrifying communities. Molecular tools available for quantifying denitrifying bacteria and assessing their diversity and activity are summarized.
Their application is illustrated with examples from marine and freshwater environments. Emerging techniques and their application to ground water studies will be discussed. Semiokapitalismus und imperiale Kontrollgesellschaft Zur Digitalisierung der Produktion am Beginn des Jahrhunderts zur Kontrolle eingesetzt werden Treatment of domestic wastewater by anaerobic denitrification Proton consumption is illustrated in Equations 1 to 4 Rittmann and McCarty, Fermentation of pulp from coffee production; Vergaerung von Pulpa aus der Kaffee- Produktion.
Harvesting of coffee berries and production of dried coffee beans produces large amounts of solid wastes. Per ton of consumable coffee beans, roughly 2 tons of spent coffee pulp are wasted at the production facilities. Coffee pulp represents a valuable source of energy and can be used for anaerobic biogas production.
In this study it was shown that coffee pulp can be anaerobically digested as a sole carbon source without further addition of co-substrates. No nutrient limitations and only a very moderate substrate inhibition have been found in concentrated pulp. The mesophilic biogas formation potential was found to be 0. In semi-continuously operated biogas reactors a high degradation of organics and a subsequent biogas production was shown at hydraulic detention times of 16 days.
Methanization of fresh pulp is technically feasible in fully mixed tank reactors as well as in plug flow reactors. Due to the presence of easily degradable carbon sources, fresh pulp will quickly show microbiological growth. Storage in the presence of ambient oxygen will result in aerobic degradation of organics in parallel with energy loss.
Additionally, anaerobic zones with methane emission will quickly occur. Therefore, it is recommended to store fresh pulp under oxygen free, lactic acid conditions silage until anaerobic treatment in the biogas reactor. Hints on cost- and energy saving during lime-sand brick production; Hinweise zur Kosten- und Energieeinsparung bei der Kalksandstein- Produktion. The publication contains hints for reduction of energy consumption and cost in lime-sand brick production. The information was compiled by Bundesverband Kalksandsteinindustrie e.
Die hier aufgefuehrten Hinweise und Anregungen entstammen den Fachdiskussionen der Meisterseminare zur Produktionstechnik aus den Jahren bis , Beratungsgespraechen fuer Mitgliedsunternehmen oder wurden dem Bundesverband Kalksandsteinindustrie eV freundlicherweise fuer die Gemeinschaftsarbeit zur Verfuegung gestellt. Denitrification across landscapes and waterscapes: Denitrification is a critical process regulating the removal of bioavailable nitrogen N from natural and human-altered systems. While it has been extensively studied in terrestrial, freshwater, and marine systems, there has been limited communication among denitrification scientists working in these individual systems.
Here, we compare rates of denitrification and controlling factors across a range of ecosystem types. We suggest that terrestrial, freshwater, and marine systems in which denitrification occurs can be organized along a continuum ranging from 1 those in which nitrification and denitrification are tightly coupled in space and time to 2 those in which nitrate production and denitrification are relatively decoupled. In aquatic ecosystems, N inputs influence denitrification rates whereas hydrology and geomorphology influence the proportion of N inputs that are denitrified. Relationships between denitrification and water residence time and N load are remarkably similar across lakes, river reaches, estuaries, and continental shelves.
Denitrification of land-based N sources is distributed somewhat differently. Within watersheds, the amount of land-based N denitrified is generally highest in terrestrial soils, with progressively smaller amounts denitrified in groundwater, rivers, lakes and reservoirs, and estuaries. A number of regional exceptions to this general trend of decreasing denitrification in a downstream direction exist, including significant denitrification in continental shelves of N from terrestrial sources.
Though terrestrial soils and groundwater are responsible for much. A new generation of medium-voltage switchboards and circuit-breakers; Eine neue Generation von Mittelspannungsschaltanlagen und -leistungsschaltern. Bereich Energieuebertragung und -verteilung. Todays market and the trend towards globalization of business both call for new products.
The authors describe the new generation of medium-voltage switchgears and circuit-breakers, along with the benefit they bring for customers. Die Verfasser beschreiben die neue Generation von Mittelspannungsschaltanlagen und -schaltern sowie deren Nutzen fuer die Anwender. Concept and Conditions of its Measurement Denitrification plays important roles in nitrogen cycling and management affecting both the environment and agricultural systems. Potential denitrification has a role in comparison of denitrification magnitudes in different soils.
This paper discusses the concept of potential denitrification in relation to denitrification rate and Modelling the soil nitrogen denitrification. The paper presents the differential equations used to compute the daily amounts of N denitrified and to compute the amount of N denitrified in a given period of time.
It shows also the equations which compute the correction factors of the maximum denitrification rate as a function of soil temperature F td , moisture F md and pH F pHd , original equations used by NICROS - nitrogen crop simulation model to describe the influence of these abiotic factors. The temperature factor, F td.
The optimum temperature for denitrification is between o C. The process is slow at temperatures below 10 o C, there is an increased inhibition below 5 o C and stop completely at 0 o C. The maximum temperature for denitrification is practically that which limits the soil microbiological activity, generally 75 o C. The following relations are used to compute the F td factor: The moisture factor, F md.
The pH factor, F pHd. Denitrification takes place at pH between and is maximum at pH between The relations used to compute the F pHd factor are: Studies on denitrification performance of tricking filters. Trickling filters are one of the oldest methods of biological waste water purification, widely used ever since they were first developed. These filters are mostly used for aerobic purification of water as highly polluted or lightly polluted reactors. While these systems are very useful for the elemination of organic pollution and the nitrification of the waste waters, denitrification of the whole plant poses considerable problems.
The question is in how far trickling filters can be used as denitrification reactors. The conditions of successful denitrification in trickling filters is investigated, denitrification performance is established. Studies were conducted in laboratory, semi-industrial and industrial scale. Modstandssvejsning finder udbredt anvendelse i industriel produktion af automobiler, fly, elektronik, radiatorer, containere, pumper m.
Denitrification of nitrate waste solutions. Growth rates for the denitrifying bacteria Pseudomonas Stutzeri were studied to minimize the time necessary to start up a bacterial denitrification reactor. Batch experiments were performed in nine ml Erlenmeyer flasks, a 7-liter fermentor, and a liter fermentor.
denitrification produktion von: Topics by oherijarutuc.gq
All reactors maintained an anaerobic environment. Initial microorganism inoculum concentration was varied over four orders of magnitude. Initial nitrate and substrate carbon concentrations were varied from to ppm and from 56 to ppm, respectively, with a carbon-to-nitrogen weight ratio of 1. In all experiments, except those with the highest initial substrate-to-bacteria ratio, no growth was observed due to substrate depletion during the lag period. In those experiments which did exhibit an increase in bacterial population, growth also stopped due to substrate depletion. A model simulating microbe growth during the induction period was developed, but insufficient data were available to properly adjust the model constants.
Because of this, the model does not accurately predict microbe growth. The metabolism of Pseudomonas Stutzeri was studied in detail. This resulted in a prediction of the denitrification stoichiometry during steady state reactor operation. Iron was found to be an important component for bacterial anabolism. Bacterial denitrification by Pseudomonas Stutzeri has been chosen as the method for removing nitrate from the effluent stream of the Y uranium purification process.
A model was developed to predict bacterial growth and carbon and nitrate depletion during the induction period and steady state operation. Modification of analytical procedures and automatic control of the pH in the reactor are recommended to improve agreement between the prediction of the model and experimental data. Further experiments in batch reactors and in steady state flow reactors are recommended to obtain more reliable kinetic rate constants.
Denitrification processes in the Arabian Sea. Heterotrophic nitrification and aerobic denitrification bacterium Distributed denitrification in a northeastern agricultural landscape. Denitrification may be an important sink of anthropogenic nitrogen N in eastern US watersheds. Denitrification occurs primarily under anaerobic conditions by heterotrophic microbes, and is therefore expected to be vigorous in wet soils containing large amounts of organic carbon.
Actual rates of denitrification , however, have been difficult to quantify, and remain one of the critical unresolved N processes at the landscape scale. We measured denitrification rates in situ along hydrologic flow paths and across gradients of hydroperiodicities, i. Denitrification rates were measured monthly using the 15N push-pull method from 14 mini-piezometers arrayed along a gradient of hydroperiodicity as indicated by a soil topographic index STI.
Mean rates of denitrification increased with STI, which ranged from 8. This relationship was used to estimate denitrification rates across the landscape and resolve a missing piece of the N budget for the farm. Improved understanding of the distribution and magnitudes of denitrification in agricultural landscapes has good potential to facilitate new, novel, and better management practices for controlling N loading to streams and rivers.
Indeed, the very areas that appear to have a propensity to harbor denitrification , i. Um unmittelbare Anwendbarkeit in der Praxi The proof is an application of simple hyperplane theorems The kinetics of denitrification in permeable sediments. Permeable sediments comprise the majority of shelf sediments, yet the rates of denitrification remain highly uncertain in these environments. Computational models are increasingly being used to understand the dynamics of denitrification in permeable sediments, which are complex environments The results showed that denitrification commenced rapidly within 30 min after the onset of anoxia and the kinetics could be well described by Michaelis-Menten kinetics with half saturation constants apparent K The ratio of sediment O-2 consumption to V-max was in the range of 0.
As a consequence, models implemented SNCR method of flue gas denitrification. Current achievements in experiments on selective non-catalytic reduction of nitrogen oxides from flue gases were presented. Some basic parameters of denitrification process temperature of reaction, contact time, molar ratio of agents, additions to reacting substances which influence the rate of nitrogen oxides emission from flue gases were analysed. On the basis of conducted experiments with calcium hydroxide and urea or calcium carbonate and urea on full-scale FGD installation on WP boiler it was found that SNCR method can be applied to simultaneous denitrification and desulfurisation of flue gases.
Physicochemical properties influencing denitrification rate and microbial activity in denitrification bioreactors. The use of N-based fertilizer will need to increase to meet future demands, yet existing applications have been implicated as the main source of coastal eutrophication and hypoxic zones.
Producing sufficient crops to feed a growing planet will require efficient production in combination with sustainable treatment solutions. N ratio and potential denitrification rate did not predict actual denitrification rate or microbial biomass. These results will assist with the widespread implementation of denitrification bioreactors to achieve significant N load reductions in large watersheds. The nitrate reduction rate as a function of groundwater temperature for all treatments. Full Text Available Nowadays, pollution caused by energy production systems is a major environmental concern.
Therefore, the development of sustainable energy sources is required. Amongst others, the microbial fuel cell MFC seems to be a possible solution because it can produce clean energy at the same time that waste is stabilized. Unfortunately, mainly due to industrial discharges, the wastes could contain nitrates, or nitrates precursors such ammonia, which could lead to lower performance in terms of electricity production.
In this work, the feasibility of coupling anodic denitrification process with electricity production in MFC and the effect of the nitrates over the MFC performance were studied. During the experiments, it was observed that the culture developed in the anodic chamber of the MFC presented a significant amount of denitrificative microorganisms. Based on these results, it can be stated that it is possible to remove nitrates and to produce energy, without negatively affecting the electrical performance, when the nitrate concentration is low.
Anaerobic columnar denitrification of high nitrate wastewater. The packing media were anthracite coal particles, whose effective diameter size ranged between 2 and 3 mm, and polypropylene Raschig rings 1. The anthracite coal proved to be the better packing media as excessive hydraulic short circuiting occurred in a x 15 cm diameter glass column packed with the polypropylene rings after 40 days operation. With anthracite coal, floatation of the bed occurred at flow rates greater than 0. Under optimum operating conditions the anthracite coal behaved as a fluidized bed.
Maximum denitrification rates were 1. Denitrification kinetics indicated that rates of denitrification became substrate inhibited at nitrate concentrations greater than 6. Effects of aquatic vegetation type on denitrification. In a microcosm 15N enrichment experiment we tested the effect of floating vegetation Lemna sp. Oxygen concentration, and thus photosynthesis, plays an important role in regulating. With the recording of the first collisions of the Large Hadron Collider LHC in November , a new era in the domain of high energy and relativistic heavy-ion physics has started.
As one of the early observables which can be addressed, the measurement of light quark flavor production is presented in this thesis. Hadrons that consist only of u, d, and s quarks constitute the majority of the produced particles in pp and Pb—Pb collisions. Their measurement forms the basis for a detailed understanding of the collision and for the answer of the question if hadronic matter undergoes a phase transition to the deconfined quark-gluon plasma at high temperatures. The basics of ultra-relativistic heavyion physics are briefly introduced in the first chapter followed by a short description of the ALICE experiment.
A particular focus is put on the unique particle identification PID capabilities as they provide the basis of the measurements which are presented in the following chapters. The particle identification vi The contribution of the quarks to nucleon spin, as measured in the inclusive deep-inelastic scattering, is not sufficient to explain the spin of the nucleon.
Thus it has to be clarified how the gluon polarization and the angular momenta of quarks and gluons contribute to the spin of the nucleon. The COMPASS collaboration determines the gluon polarization from cross section asymmetries in photon-gluon fusion processes using open charm production or the production of hadron pairs with large transverse momenta.
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Efficiency and annual power production of photovoltaic modules; Wirkungsgrad und jaehrliche Strom- Produktion von Photovoltaik-Modulen. It consists of a sun-tracker and a PC-based measurement system. The sun-tracker is used to orient test modules continuously towards the sun. The paper describes tests performed under constant irradiation and various module temperatures, thus allowing the temperature coefficient of the efficiency to be determined. Figures on the efficiencies of three commercially-available panels are presented for different irradiance levels. The results are presented in graphical form and commented on.
Production of ultra cold neutrons with a solid deuterium converter; Produktion von ultrakalten Neutronen mit einem festen Deuteriumkonverter. Spontaneous breaking of fundamental symmetries is an attractive topic in modern particle physics. Understanding qualitative and quantitative the parameters involved in these kind of processes could help to explain the unbalanced presence in the universe of matter baryons with respect to antimatter anti-baryons.
In this work the setup of a source for ultra cold neutrons with a solid deuterium converter is described, which serves as a prototype for a new, strong UCN source, that is currently designed and constructed at the FRMII in Garching. The prototype source has been taken into operation and important parameters have been measured. These experimental results have been compared with theoretical models to prove calculations for the performance of the new source at the FRMII.
This study tries to fill this gap partially by empirically examining the use of color through a number of receptive, productive and reflexive. The modern consumer is very much interested in healthy food. The reason is that a special group of consumers is focusing more and more attention on health and nutrition problems. Further, there is increased emphasis on education in food science at universities as well as polytechnics. For some years worldwide dietary goals are published with the intention to reduce nutrition-based sickness. For the first time in our nutrition report , clear proposals for optimal nutrition were formulated.
Pipetten og dens indstilling vises. Assessment of denitrification process in lower Ishikari river system, Japan. Sediment denitrification rate and its role in removal of dissolved nitrate load in lower Ishikari river system were examined. Denitrification rate were measured using acetylene inhibition technique on the sediment samples collected during August July The denitrification rate varied from 0.
Denitrification rate showed positive correlation with dissolved nitrate concentration in the river basin, indicating overlying water column supplied nitrate for the sediment denitrification processes. Nutrient enrichment experiments result showed that denitrification rate increased significantly with addition of nitrate in case of samples collected from Barato Lake however no such increase was observed in the samples collected from Ishikari river main channel and its major tributaries indicating that factors other than substrate concentration such as population of denitrifier and hydrological properties of stream channel including channel depth and flow velocity may affects the denitrification rate in lower Ishikari river system.
Denitrification rate showed no significant increase with the addition of labile carbon glucose , indicating that sediment samples had sufficient organic matter to sustain denitrification activity. This study was carried out to fill the gap present in the availability of riverine denitrification rate measurement and its role in nitrogen budget from Japanese rivers characterize by small river length and high flow rate.
Denitrification prevails over anammox in tropical mangrove sediments Goa, India. At Divar, denitrification was approx 3 times higher than at Tuvem with maximum activity of Studies on benthic denitrification in the Chwaka Bay mangrove Spatial variations in denitrification rates were due to variations in concentration levels of organic matter and possibly to disproportionate competition for inorganic nitrogen between denitrifiers and benthic autotrophs among sites.
There were no seasonal differences in denitrification rates. Results from the present study A simple model for simultaneous methanogenic- denitrification systems. We describe a useful and simple model for studies of simultaneous methanogenic- denitrification M-D systems. One equation predicts an inverse relationship between the percentage of electron donor channeled into dissimilatory denitrification and the loading ratio X given by grams degradable COD per Warming can boost denitrification disproportionately due to altered oxygen dynamics.
Global warming and the alteration of the global nitrogen cycle are major anthropogenic threats to the environment. Denitrification , the biological conversion of nitrate to gaseous nitrogen, removes a substantial fraction of the nitrogen from aquatic ecosystems, and can therefore help to reduce eutrophication effects. However, potential responses of denitrification to warming are poorly understood. Although several studies have reported increased denitrification rates with rising temperature, the impact of temperature on denitrification seems to vary widely between systems. We explored the effects of warming on denitrification rates using microcosm experiments, field measurements and a simple model approach.
Our results suggest that a three degree temperature rise will double denitrification rates. By performing experiments at fixed oxygen concentrations as well as with oxygen concentrations varying freely with temperature, we demonstrate that this strong temperature dependence of denitrification can be explained by a systematic decrease of oxygen concentrations with rising temperature. Warming decreases oxygen concentrations due to reduced solubility, and more importantly, because respiration rates rise more steeply with temperature than photosynthesis. Our results show that denitrification rates in aquatic ecosystems are strongly temperature dependent, and that this is amplified by the temperature dependencies of photosynthesis and respiration.
Our results illustrate the broader phenomenon that coupling of temperature dependent reactions may in some situations strongly alter overall effects of temperature on ecological processes. Denitrification in the water column of the central Baltic Sea. Removal of fixed nitrogen in the water column of the eastern Gotland Basin, central Baltic Sea, was studied during two cruises in September and August The water column was stratified with anoxic sulfidic bottom water meeting oxic nitrate containing water at the oxic—anoxic interface In situ denitrification ranged from 0.
Even with an active denitrification layer of 3—6 m thickness the pelagic denitrification per unit area clearly exceeded sediment denitrification rates elsewhere in the Baltic Sea. When extrapolated to the entire Baltic Proper BP denitrification in the water column was in the range of Plant effects on soil denitrification - a review of potential mechanisms.
Denitrification is a microbial process occurring in soils, both producing and consuming the potent greenhouse gas nitrous oxide NO , competing for nitrate with plants and hydrological leaching pathways, removing nutrients and reactive nitrogen from the biosphere, and closing the global nitrogen cycle. Despite its obvious importance, denitrification remained among the least well quantified biogeochemical processes in soils.
This is due to enormous methodological difficulties involved in the direct quantification of soil microbial denitrification rates mainly with regard to the terminal product N2 and the denitrification nitrogen gas product ratios NO: N2 , Plants may affect denitrification through a myriad of mechanisms such as e. However, plant effects on denitrification so far hardly were quantified so that the actual extent of plant control on denitrification is largely unknown. Here, we summarize the current knowledge on mechanisms how plants can affect denitrification rates and N gas product ratios in soils at temporal scales from hours to days and years.
We review earlier research to quantify plant effects on denitrification as well as critically discuss the limited methods currently available to quantify plant-soil-denitrifier interactions. Finally, we provide pointers to use plants as tools to manage denitrification , e. Von Start-ups lernen - Methoden und Entwicklungsprozesse, die Jungunternehmen erfolgreich machen. Disruptoren hervor, die jede Branche betreffen und so gut wie keinen Lebensbereich auslassen.
Zunehmend adaptieren etablierte Unternehmen innovative Entwicklungsprozesse und Methoden. Development of a method for in situ measurement of denitrification in aquifers using 15N tracer tests and membrane inlet mass spectrometry. A small part of the sample was directly conducted in the membrane inlet of our mass spectrometer and the other part was collected in serum bottles which were immediately sealed with rubber septa and stored for later measurement by isotope ratio mass spectrometer IRMS.
Because of the online measurement with MIMS we were able to see during the experiment if and when the production of the labeled denitrification products started. Later-on this approach will be used in the field. Here, the MIMS-technique will be especially advantageous, because the success of tracer test can be immediately seen during in situ sampling. Denitrification in the karstic Floridan Aquifer. Nitrate concentrations in the karstic Floridan Aquifer have increased dramatically over the past 50 years, owing to agricultural intensification and urbanization. Due to low concentrations of organic matter and moderately oxic conditions in the Floridan Aquifer, groundwater denitrification has been assumed to be negligible.
We modeled the physical processes recharge temperature, dissolution of excess air driving super-saturation of N2 gas using Ne and Ar where data describing Ne were available. Ar concentrations were correlated closely with recharge temperature, which ranged from Estimates of physical mechanisms allowed calculation of expected N2 concentrations that were compared to observed N2 concentrations. Where Ne data were unavailable, we assumed excess air equal to the empirical average.
Overall, observed N2 exceeded expectations based on physical processes in 33 of 47 cases; average excess N2 was 0. Low DOC concentrations indicate that alternative electron donors may fuel nitrate reduction. Scaling to regional estimates of N2 production based on springs discharge and DO concentrations indicates that subsurface denitrification may account for some of the imbalance in springshed nutrient budgets. Denitrification of acid wastes from uranium purification processes.
Laboratory and pilot-plant investigations have shown the technical feasibility of removing nitrates from neutralized acid wastes from uranium purification processes by biological denitrification , a dissimilatory process in which the nitrate ion is reduced to nitrogen gas by specific bacteria. The process requires anaerobic conditions and an organic carbon source, as well as other life-sustaining constituents.
These denitrification studies produced process design information on a columnar denitrification plant and on continuous-flow, stirred-bed reactors. Denitrification , using packed columns, was found to be desirable for soluble salts, such as those of sodium and ammonium; denitrification , using stirred reactors, was found to be desirable for mixtures containing insoluble salts, such as those of calcium and aluminum.
Packed columns were found to have denitrification rates ranging up to grams of nitrate per day per cubic decimeter of column volume; stirred-bed reactors have been shown to have reaction rates near 10 grams of nitrate per day per cubic decimeter of reactor volume. The continuous-flow, stirred-bed reactors were selected for scaleup studies because of the solids-removal problems associated with packed columns when operating on feeds containing high concentrations of insoluble salts or ions which form insoluble salts with the products of the denitrification reaction.
Denitrification in groundwater at uranium mill tailings sites. Microbial denitrification , the transformation of nitrate to nitrogen gas, may be occurring in groundwater at several UMTRA sites. Denitrification is a biologically mediated process whereby facultative anaerobes use nitrate for respiration under anaerobic conditions. Denitrifying bacteria are ubiquitous in soils, sediments, and water.
Denitrification requires nitrate, organic carbon, oxygen-limiting conditions, and trace nutrients, especially phosphorus. The lack of organic carbon is the most common limiting factor for denitrification. Denitrification occurs under a limited range of temperature and pH. The uranium milling processes used at UMTRA sites provided a readily available source of carbon and nitrates for denitrifying bacteria. At the Maybell, Colorado, site, the denitrifying organisms Pseudomonas, Flavobacterium and Acinetobacter were identified in core samples of materials from beneath the tailings.
In addition, microcosm experiments simulating aquifer conditions beneath the tailings pile showed an average 40 percent decrease in nitrate concentrations over 13 days. At the New Rifle, Colorado, site, aquifer conditions appear favorable for denitrification. Nitrate and organic carbon are readily available in the groundwater, and redox conditions beneath and downgradient of the tailings pile are relatively anoxic.
Downgradient from the tailings, total nitrogen is being removed from the groundwater system at a greater rate than the geochemically conservative anion, chloride. This removal may be due to denitrification and adsorption of ammonium onto clay and silt particles. Ellis Von Creveld Syndrome. Lars von Triers film. Afhandlingen analyserer de enkelte films stil, virkningsstrategi og betydningsdannelse Elevers produktion af multimodale tekster. Hvad ved vi og hvad mangler vi? Teoretisk beskrives multimodalitet med udgangspunkt i New London Groups programartikel fra og den udvikling af multimodalitet, som gruppen omkring Kress og van Leeuwen har bidraget med.
Working with multimodal texts in the mother tongue subject is included in the curricula for all three Scandinavian countries. The results of the research will be presented in the following five themes: Co-combustion of sewage sludge; Mitverbrennung von Klaerschlamm. Thermal sewage disposal pursues the following aims: The thermal treatment chain should be as short as possible; intermediate stages in separate reactors such as digestion, drying, degasification or gasification should be avoided if the material is ultimately to be combusted.
The present paper examines and assesses the co-combustion of sewage sludge. Die thermische Behandlungskette sollte moeglichst kurz sein; Zwischenschritte wie Faulung, Trocknung, Ent- oder Vergasung in getrennten Reaktoren sollten vermieden werden, wenn letztendlich doch verbrannt wird. Das Verfahren der Mitverbrennung von Klaerschlamm wird hier untersucht und bewertet. Mechatronics for production and logistics; Antriebsloesungen.
Mechatronik fuer Produktion und Logistik. Highly automated production and logistic systems require mechatronic drives. The book describes how industrial production and logistics work, and how the appropriate drive systems should be designed. The function of the mechanical and electronic elements of a drive system is described, including the required software, and the fundamentals of dimensioning are gone into. The authors also discuss engineering, reliability and important life cycle aspects.
Applications in material flow and handling technology, in continuous and clocked production lines and finishing processes are presented in twelve sections offering different drive solutions for the motor, current inverter and software, transmission system and mechanical elements. The specific requirements and functionalities of these twelve solutions are presented. The focus is on energy conversion with controlled electric drive systems.
Dieses Buch beschreibt, wie die industrielle Fertigung und Logistik arbeitet und wie die hierzu erforderlichen Antriebsloesungen aufgebaut sind. Es wird die Funktionsweise der mechanischen und der elektronischen Elemente eines Antriebssystems einschliesslich der Software beschrieben und ihre Dimensionierungsgrundlagen behandelt. Die Autoren gehen darueber hinaus auf das Engineering, die Zuverlaessigkeit und auf wichtige Aspekte des Lebenszyklus ein. Die Vielzahl der Anwendungen in der Materialfluss- und der Handhabungstechnik, in kontinuierlichen und getakteten Produktionslinien sowie fuer Bearbeitungsprozesse wird in insgesamt zwoelf Antriebsloesungen eingeteilt.
Diese umfassen den Motor, den Umrichter mit seiner Software, das Getriebe sowie mechanische Antriebselemente. Es werden die spezifischen Anforderungen und die Funktionalitaet dieser zwoelf Loesungen dargestellt. Dabei konzentrieren sich die Autoren auf die Energieumsetzung mit geregelten elektrischen. Transport zonation limits coupled nitrification- denitrification in permeable sediments. The measured two-dimensional profiles correlate with computational model simulations, showing a deep pool of N-2 gas forming, and being advected to the surface below ripple peaks. Further isotope pairing calculations on these data indicate that coupled nitrification The approach allowed for new detailed insight into subsurface denitrification zones in complex permeable sediments Denitrification and Ecosystem Services: Mapping and Modeling Conservation Effects.
Precision conservation is the latest effort to increase higher efficiency in agricultural best management practices by considering the spatial and temporal variability in agroecosystems. The authors have developed a framework for incorporating the ecosystem service of denitrification into an existing precision conservation mapping tool.
The model identifies areas of denitirification and quantifies potential denitrification when a conservation practice is adopted. Linking denitrification and infiltration rates during managed groundwater recharge. We quantify relations between rates of in situ denitrification and saturated infiltration through shallow, sandy soils during managed groundwater recharge. We used thermal methods to determine time series of point-specific flow rates, and chemical and isotopic methods to assess denitrification progress.
Denitrification was not detected at times and locations where the infiltration rate exceeded a threshold of 0. Pore water profiles of oxygen and nitrate concentration indicated a deepening of the redoxocline at high flow rates, which reduced the thickness of the zone favorable for denitrification.
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Denitrification rates were positively correlated with infiltration rates below the infiltration threshold, suggesting that for a given set of sediment characteristics, there is an optimal infiltration rate for achieving maximum nitrate load reduction and improvements to water supply during managed groundwater recharge. The extent to which results from this study may be extended to other managed and natural hydrologic settings remains to be determined, but the approach taken in this study should be broadly applicable, and provides a quantitative link between shallow hydrologic and biogeochemical processes.
Using natural biomass microorganisms for drinking water denitrification. Among the methods that are studied to eliminate nitrate from drinking water, biological denitrification is an attractive strategy. Although several studies report the use of denitrifying bacteria for nitrate removal, they usually involve the use of sewage sludge as biomass to obtain the microbiota.
In the present study, denitrifying bacteria was isolated from bamboo, and variable parameters were controlled focusing on optimal bacterial performance followed by physicochemical analysis of water adequacy. In this way, bamboo was used as a source of denitrifying microorganisms, using either Immobilized Microorganisms IM or Suspended Microorganisms SM for nitrate removal. In addition, operational stability and denitrification kinetics were evaluated. Microorganisms present in the biomass responsible for denitrification were identified as Proteus mirabilis.
The denitrified water was submitted to physicochemical treatment such as coagulation and flocculation to adjust to the parameters of color and turbidity to drinking water standards. The use of SM provided superior denitrification efficiency using ethanol The evaluation of the operational stability allowed 12 cycles of biomass reuse using the IM and 9 cycles using the SM.
After physical-chemical treatment, only SM denitrified water remained within drinking water standards parameters of color and turbidity. The investigations presented here aimed at assessing and improving the accuracy of the GOME measurements of sun-standardized and absolute radiation density and the derived data products. For this purpose, the GOME data were compared with measurements pf terrestrial, airborne and satellite-borne systems. For scientific reasons, the measurements will focus on the medium and high latitudes of both hemispheres, although equatorial regions were investigated as well.
In the first stage, operational data products of GOME were validated, i. Das Ziel dieses Vorhabens ist es, die Genauigkeit der von GOME durchgefuehrten Messungen von sonnennormierter und absoluter Strahlungsdichte sowie der aus ihnen abgeleiteten Datenprodukte zu bewerten und zu verbessern. Aus wissenschaftlichen Gruenden wird der Schwerpunkt auf Messungen bei mittleren und hohen Breitengraden in beiden Hemisphaeren liegen.
Jedoch wurden im Laufe des Projektzeitraumes auch Regionen in Aequatornaehe untersucht. Das Material wurde im December in Manila-bay gefischt und befindet sich in bestem. Impact of chloride on denitrification potential in roadside wetlands. Developed landscapes are exposed to changes in hydrology and water chemistry that limit their ability to mitigate detrimental impacts to coastal water bodies, particularly those that result from stormwater runoff. The elevated level of impervious cover increases not only runoff but also contaminant loading of nutrients, metals, and road salt used for deicing to water bodies.
Here we investigate the impact that road salt has on denitrification in roadside environments. The difference could not be attributed to other significant changes in conditions, such as DOC concentrations, N species concentrations, or pH levels. The shifts in denitrifying communities seem to minimize the decrease in denitrification rates in the wetlands previously exposed to Cl.
Microbial ecology of denitrification in biological wastewater treatment. Globally, denitrification is commonly employed in biological nitrogen removal processes to enhance water quality. However, substantial knowledge gaps remain concerning the overall community structure, population dynamics and metabolism of different organic carbon sources. This systematic review provides a summary of current findings pertaining to the microbial ecology of denitrification in biological wastewater treatment processes. DNA fingerprinting-based analysis has revealed a high level of microbial diversity in denitrification reactors and highlighted the impacts of carbon sources in determining overall denitrifying community composition.
Stable isotope probing, fluorescence in situ hybridization, microarrays and meta-omics further link community structure with function by identifying the functional populations and their gene regulatory patterns at the transcriptional and translational levels. This review stresses the need to integrate microbial ecology information into conventional denitrification design and operation at full-scale. Some emerging questions, from physiological mechanisms to practical solutions, for example, eliminating nitrous oxide emissions and supplementing more sustainable carbon sources than methanol, are also discussed.
A combination of high-throughput approaches is next in line for thorough assessment of wastewater denitrifying community structure and function. Though denitrification is used as an example here, this synergy between microbial ecology and process engineering is applicable to other biological wastewater treatment processes. Full Text Available Denitrification is a respiratory process that produces nitrous oxide as an intermediate, which may escape to the atmosphere before its reduction to dinitrogen through the nitrous oxide reductase NosZ.
In this work, the denitrification process carried out by Paracoccus denitrificans PD has been explored through a quantitative proteomic analysis. Under anaerobic conditions, with nitrate as sole nitrogen source, the synthesis of all the enzymes involved in denitrification , the respiratory nitrate, nitrite, nitric oxide, and nitrous oxide reductases, was increased.
However, the periplasmic and assimilatory nitrate reductases decreased. Synthesis of transporters for alcohols, D-methionine, sulfate and copper, most of the enzymes involved in the tricarboxylic acid cycle, and proteins involved in other metabolic processes like lysine catabolism, fatty acids degradation and acetyl-CoA synthesis, was increased during denitrification in P.
As consequence, an enhanced production of the central metabolite acetyl-CoA was observed. After establishing the key features of the denitrification proteome, its changes by the influence of a competitive electron acceptor, oxygen, or competitive nitrogen source, ammonium, were evaluated. Inhibition of existing denitrification enzyme activity by chloramphenicol. Chloramphenicol completely inhibited the activity of existing denitrification enzymes in acetylene-block incubations with i sediments from a nitrate-contaminated aquifer and ii a continuous culture of denitrifying groundwater bacteria.
Control flasks with no antibiotic produced significant amounts of nitrous oxide in the same time period. Amendment with chloramphenicol after nitrous oxide production had begun resulted in a significant decrease in the rate of nitrous oxide production. Short-term time courses of nitrate consumption and nitrous oxide production in the presence of acetylene with P.
Complete or partial inhibition of existing enzyme activity is not consistent with the current understanding of the mode of action of chloramphenicol or current practice, in which the compound is frequently employed to inhibit de novo protein synthesis during the course of microbial activity assays. The results of this study demonstrate that chloramphenicol amendment can inhibit the activity of existing denitrification enzymes and suggest that caution is needed in the design and interpretation of denitrification activity assays in which chloramphenicol is used to prevent new protein synthesis.