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the phylogeny of purple bacteria: the alpha subdivision.the technique of oligonucleotide cataloging shows the purple photosynthetic eubacteria to comprise three major subdivisions, temporarily called alpha, beta, and gamma--previously designated groups i-iii by gibson et al. (1979). each subdivision contains a number of non-photosynthetic genera in addition to the photosynthetic ones. the alpha subdivision, the subject of the present report, contains most but not all of the species that fall into the classically defined genera rhodospirillum, rhodo ...198411541974
a comparative survey of several bacterial aa3-type cytochrome c oxidases.the aa3-type cytochrome c oxidases purified from nitrobacter agilis, thiobacillus novellus, nitrosomonas europaea, and pseudomonas am 1 were compared. they have haem a and copper atom as the prosthertic groups and show alpha and gamma absorption peaks at around 600 and 440 nm, respectively. each oxidase molecule is composed of two kinds of subunits. the n. agilis oxidase has 2 moles of haem a and 2 atoms of copper in the minimal structural unit composed of one molecule each of the two kinds of s ...19852991467
cytochrome c oxidase of pseudomonas am 1: purification, and molecular and enzymatic properties.cytochrome c oxidase (cytochrome aa3-type) [ec 1.9.3.1] was purified from pseudomonas am 1 to an electrophoretically homogeneous state and some of its properties were studied. the oxidase showed absorption peaks at 428 and 598 nm in the oxidized form, and at 442 and 604 nm in the reduced form. the co compound of the reduced enzyme showed peaks at 432 and 602 nm. the enzyme molecule was composed of two kinds of subunits with molecular weights of 50,000 and 30,000 and it contained equimolar amount ...19852999096
[structural, functional and evolutional aspects of nitrobacter agilis cytochrome c]. 19852999879
n-terminal amino acid sequence of cytochrome c-552 from nitrosomonas europaea.nitrosomonas europaea is an ammonia-oxidizing bacterium which contains multiple c-type cytochromes. few of these components have been assigned physiological roles, but on the basis of molecular weight and redox potential cytochrome c-552 has been considered to be an analogue of the mitochondrial cytochrome-c family of proteins. we present the n-terminal amino acid sequence (47 residues) of cytochrome c-552 and show that this protein is most closely related to the group of small cytochrome-c comp ...19863004498
[subordination of the taxa of gram-negative bacteria determined by numerical analysis methods].various numerical methods were used to estimate the coordination of taxa of gram-negative aerobic and facultative anaerobic organoheterotrophic and chemolithotrophic bacteria. stable phena were found to be formed by cultures belonging to the families rhizobiaceae, halobacteriaceae, enterobacteriaceae, nitrobacteriaceae (except the genus nitrobacter), and methylomonadaceae (except the genus methylococcus). the unstable position was found in the genera thermus, zoogloea, xanthomonas, sulfolobus, m ...19863523170
oxygen exchange between nitrate molecules during nitrite oxidation by nitrobacter.during oxidation of nitrite, cells of nitrobacter winogradskyi are shown to catalyze the active exchange of oxygen atoms between exogenous nitrate molecules (production of 15n16/18o3- during incubation of 14n16/18o3-, 15n16o3-, and 15n16o2- in h216o). little, if any, exchange of oxygens between nitrate and water also occurs (production of 15n16/18o3- during incubation of 15n16o3- and 14n16o2- in h218o). 15n species of nitrate were assayed by 18o-isotope shift in 15n nmr. taking into account the ...19863733717
catalysis of intermolecular oxygen atom transfer by nitrite dehydrogenase of nitrobacter agilis.nitrobacter agilis, which contains a very active nitrite dehydrogenase, was studied in vivo under anaerobic conditions by the 15n nmr technique. when incubated with equimolar 15no3- and unlabeled nitrite (or 15no2- and unlabeled nitrate) the bacterium catalyzed an isotope exchange reaction at rates about 10% those observed in the nitrite oxidase assay. when incubated with 18o-labeled 15no2- and 18o-labeled 15no3-, the 18o was observed to exchange at similar rates from both species into water. fi ...19863733718
measurement of proton pump activity of the thermophilic bacterium ps3 and nitrobacter agilis at the cytochrome oxidase level using total membrane and heptyl thioglucoside.it is possible to prepare liposomal vesicles by solubilization of total bacterial membranes with n-heptyl beta-d-thioglucoside followed by reconstitution into proteoliposomes by a freeze-thaw-sonication procedure with soybean phospholipids. the resulting proteoliposomes from total membrane fraction of sufficiently aerated cells of the thermophilic bacterium ps3 containing cytochrome aa3 showed a reasonable h+ pumping activity upon addition of reduced cytochrome c. on the other hand, the proteoli ...19862883179
inhibitor evaluation with immobilized nitrobacter agilis cells.nitrobacter agilis was entrapped in calcium alginate beads and used as a floating bed supplied with a continuous flow of nitrite medium. complete nitrite oxidation was achieved within 30 h, and the system could be maintained for at least 210 h. the immobilized nitrobacter system was subjected to sulfur oxyanions, acidity, and metal ions. thiosulfate and tetrathionate (up to 20 mm each) did not inhibit the nitrite oxidation activity. a low ph of 4.2 resulted in the complete cessation of nitrite o ...198616347230
nitrifying bacteria in wastewater reservoirs.deep wastewater reservoirs are used throughout israel to store domestic wastewater effluents for summer irrigation. these effluents contain high concentrations of ammonia (</=5 mm) that are frequently toxic to photosynthetic microorganisms and that lead to development of anoxic conditions. population dynamics of nitrifying bacteria and rates of nitrification were studied in two wastewater reservoirs that differed in organic load and degree of oxygenation and in the laboratory under controlled co ...198716347319
5s rrna sequences from nitrobacter winogradskyi, caulobacter crescentus, stella humosa and verrucomicrobium spinosum. 19873684605
nitrobacter winogradskyi cytochrome a1c1 is an iron-sulfur molybdoenzyme having hemes a and c.cytochrome a1c1 (nitrite-cytochrome c oxidoreductase) purified from nitrobacter winogradskyi (formerly n. agilis) contained molybdenum, non-heme iron, and acid-labile sulfur in addition to hemes a and c; it contained 1 mol of heme a, 4-5 g atoms of non-heme iron, 2-5 g atoms of acid-labile sulfur, and 1-2 g atoms of molybdenum per mol of heme c, but did not contain copper. the fluorescence spectra of the molybdenum cofactor derivative prepared from cytochrome a1c1 were very similar to those of t ...19872828343
the nitrite oxidizing system of nitrobacter winogradskyi.cytochrome components which participate in the oxidation of nitrite in nitrobacter winogradskyi have been highly purified and their properties studied in detail. cytochrome a1c1 is an iron-sulphur molybdoenzyme which has haems a and c and acts as a nitrite-cytochrome c oxidoreductase. cytochrome c-550 is homologous to eukaryotic cytochrome c and acts as the electron mediator between cytochrome a1c1 and aa3-type cytochrome c oxidase. the oxidase is composed of two kinds of subunits, has two molec ...19882856189
a phylogenetic survey of budding, and/or prosthecate, non-phototrophic eubacteria: membership of hyphomicrobium, hyphomonas, pedomicrobium, filomicrobium, caulobacter and "dichotomicrobium" to the alpha-subdivision of purple non-sulfur bacteria.the phylogenetic position of various budding and/or or prosthecate gram-negative eubacteria was determined by different methods. members of the genera hyphomicrobium, filomicrobium, pedomicrobium were investigated by 16s rrna cataloguing, a 1373 nucleotide long portion of the 16s rrna was sequenced from hyphomicrobium vulgare and the 5s rrnas were analyzed from two hyphomicrobium strains, hyphomonas polymorpha and caulobacter crescentus. comparison with published sequences indicated a membership ...19882455491
different lipid a types in lipopolysaccharides of phototrophic and related non-phototrophic bacteria.lipid a analyses confirm not only the present taxa of the purple nonsulfur bacteria (formerly rhodospirillaceae), but also phylogenetical relatedness of distinct phototrophic to distinct non-phototrophic bacteria, as was suggested by cataloguing 16s rrna. for example, lipid a with ester-bound 3-oh-10:0 and the rare amide-linked 3-oxo-14:0 is common to the phototrophic rhodobacter capsulatus and rhodobacter sphaeroides and also to paracoccus denitrificans and thiobacillus versutus. 'lipid adag' ( ...19883078741
[biology of chemoautotrophs]. 19883150584
an acidophilic and a neutrophilic nitrobacter strain isolated from the numerically predominant nitrite-oxidizing population of an acid forest soil.two physiologically and serologically distinct strains of chemoautotrophic nitrite-oxidizing bacteria were isolated as numerically predominant members of the nitrite-oxidizer population of an undisturbed forest soil with a ph range of 4.3 to 5.2. one isolate responded as a neutrophile, characteristic of the family nitrobacteraceae, and cross-reacted strongly with fluorescent antibody to nitrobacter strain engel. the second isolate responded as an acidophile in pure culture, demonstrated maximal ...198816347664
an analysis of nitrification during the aerobic digestion of secondary sludges.investigations were undertaken to study the occurrence and progress of nitrification during aerobic digestion of activated sludge in a wide range of initial concentrations of total solids (1000 to 80 000 mg litre(-1), initial ph range of 4.5 to 10.4 and digestion temperature range of 5 degrees to 60 degrees c. batch aerobic digestion studies on activated sludge grown on wastewater (enriched with organic solids from human excretal material) indicate that almost complete elimination of the 'biodeg ...198915092439
[the amount of nitrogenous oxygen demand (nod) in bod--study on effluents and influent from biological treatment plants and river waters in kitakyushu area].bod (biochemical oxygen demand) is utilized widely as an index of water quality. however, nitrification is a cause of significant errors in measuring bod, particularly when a large population of nitrifying organisms are existing in water such as effluents from biological treatment plants. in this case, the use of a nitrification inhibitor is recommended, but it is not used commonly. in order to investigate the amount of nitrogenous oxygen demand (nod) which is caused by nitrification, bod with a ...19902287844
cytochromes c of nitrobacter winogradskyi and thiobacillus novellus: structure, function and evolution.the amino acid sequences of thiobacillus novellus and nitrobacter winogradskyi cytochromes c have been compared with those of cytochromes c from several other organisms. the two bacterial cytochromes resemble eukaryotic cytochromes c; 49 amino-acid residues are identical between t. novellus and horse cytochromes c, and 50 residues identical between n. winogradskyi and horse cytochromes c. however, their reactivity with cow cytochrome c oxidase is about 80% lower than the reactivity of eukaryotic ...19911646018
16s rrna sequences of bartonella bacilliformis and cat scratch disease bacillus reveal phylogenetic relationships with the alpha-2 subgroup of the class proteobacteria.the primary structures of 16s rrnas of bartonella bacilliformis, an isolate of the cat scratch disease (csd) bacillus, and a strain phenotypically similar to the csd bacillus were determined by reverse transcriptase sequencing. these microorganisms were found to be members of the alpha-2 subgroup of the class proteobacteria. the sequence from b. bacilliformis was most closely related to the rrna of rochalimaea quintana (91.7% homology), the etiologic agent of trench fever. the sequence from the ...19911719021
purification and characterization of atpase from nitrobacter winogradskyi.an atpase was purified from nitrobacter winogradskyi, and some of its molecular and enzymatic properties were determined. the enzyme was composed of two subunits of 64 and 59 kda, respectively. the enzyme had its ph optimum at 9.5 and showed a specific activity of 7 units per mg protein. this activity was about 14% and 18% of that of f1-atpases obtained from escherichia coli and sulfolobus acidocaldarius, respectively. the enzyme was 29% and 6% inhibited by 100 microm dicyclohexylcarbodiimide (d ...19911834519
physical, chemical and immunological properties of the bacterioferritins of escherichia coli, pseudomonas aeruginosa and azotobacter vinelandii.the 70-amino-acid-residue n-terminal sequence of the bacterioferritin (bfr) of azotobacter vinelandii was determined and shown to be highly similar to the n-terminal sequences of the escherichia coli and nitrobacter winogradskyi bacterioferritins. electrophoretic and immunological analyses further indicate that the bacterioferritins of e. coli, a. vinelandii and pseudomonas aeruginosa are closely related. a novel, two-subunit assembly state that predominates over the 24-subunit form of bfr at lo ...19911904771
competition for ammonium between nitrifying and heterotrophic bacteria in dual energy-limited chemostats.the absence of nitrification in soils rich in organic matter has often been reported. therefore, competition for limiting amounts of ammonium between the chemolithotrophic ammonium-oxidizing species nitrosomonas europaea and the heterotrophic species arthrobacter globiformis was studied in the presence of nitrobacter winogradskyi in continuous cultures at dilution rates of 0.004 and 0.01 h. ammonium limitation of a. globiformis was achieved by increasing the glucose concentration in the reservoi ...199116348588
growth and substrate consumption of nitrobacter agilis cells immobilized in carrageenan: part 1. dynamic modeling.the modeling of the growth of nitrobacter agilis cell immobilized in kappa-carrageenan is presented. a detailed description is given of the modeling of internal diffusion and growth of cells in the support matrix in addition to external mass transfer resistance. the model predicts the substrate and biomass profiles in the support as well as the macroscopic oxygen consumption rate of the immobilized biocatalyst in time. the model is tested by experiments with continuously operated airlift loop re ...199118600755
growth and substrate consumption of nitrobacter agilis cells immobilized in carrageenan: part 2. model evaluation.a dynamic model that predicts substrate and biomass concentration profiles across gel beads and from that the overall substrate consumption rate by the gel beads containing growing cells was evaluated with immobilized nitrobacter agilis cells in an airlift loop reactor with oxygen as the limiting substrate. the model predictions agreed well with the observed oxygen consumption rates at three different liquid phase oxygen concentrations. image analysis showed that 90% of the immobilized cells aft ...199118600756
effects of grazing by flagellates on competition for ammonium between nitrifying and heterotrophic bacteria in chemostats.the enhanced mineralization of organic nitrogen by bacteriophagous protozoa is thought to favor the nitrification process in soils, in which nitrifying bacteria have to compete with heterotrophic bacteria for the available ammonium. to obtain more insight into this process, the influence of grazing by the bacteriovorous flagellate adriamonas peritocrescens on the competition for limiting amounts of ammonium between the ammonium-oxidizing species nitrosomonas europaea and the heterotrophic specie ...199216348722
competition for ammonium between nitrifying and heterotrophic bacteria in continuously percolated soil columns.although the absence of nitrate formation in grassland soils rich in organic matter has often been reported, low numbers of nitrifying bacteria are still found in these soils. to obtain more insight into these observations, we studied the competition for limiting amounts of ammonium between the chemolithotrophic ammonium-oxidizing species nitrosomonas europaea and the heterotrophic species arthrobacter globiformis in the presence of nitrobacter winogradskyi with soil columns containing calcareou ...199216348787
characterization of natural populations of nitrobacter spp. using pcr/rflp analysis of the ribosomal intergenic spacer.dna sequences from the intergenic spacer (igs) region of the ribosomal operon were amplified by the polymerase chain reaction (pcr) technique using two primers derived from 16s and 23s rrna conserved sequences. the pcr products, cleaved by 4 base cutting restriction enzymes, were used to differentiate nitrobacter strains. this method offered a convenient alternative to serological testing for characterization of nitrobacter isolates and enabled a large number of strains to be genotypically chara ...19921347989
quantitative determination of the spatial distribution of nitrosomonas europaea and nitrobacter agilis cells immobilized in kappa-carrageenan gel beads by a specific fluorescent-antibody labelling technique.a novel technique, combining labelling and stereological methods, for the determination of spatial distribution of two microorganisms in a biofilm is presented. cells of nitrosomonas europaea (atcc 19718) and nitrobacter agilis (atcc 14123) were homogeneously distributed in a kappa-carrageenan gel during immobilization and allowed to grow out to colonies. the gel beads were sliced in thin cross sections after fixation and embedding. a two-step labelling method resulted in green fluorescent colon ...199316348970
effects of grazing by flagellates on competition for ammonium between nitrifying and heterotrophic bacteria in soil columns.the enhanced mineralization of immobilized nitrogen by bacteriophagous protozoa has been thought to favor the nitrification process in soils in which nitrifying bacteria must compete with heterotrophic bacteria for the available ammonium. to obtain more insight into this process, the influence of grazing by the flagellate adriamonas peritocrescens on the competition for ammonium between the chemolithotrophic species nitrosomonas europaea and the heterotrophic species arthrobacter globiformis in ...199316348988
selective inhibition of ammonium oxidation and nitrification-linked n(2)o formation by methyl fluoride and dimethyl ether.methyl fluoride (ch(3)f) and dimethyl ether (dme) inhibited nitrification in washed-cell suspensions of nitrosomonas europaea and in a variety of oxygenated soils and sediments. headspace additions of ch(3)f (10% [vol/vol]) and dme (25% [vol/vol]) fully inhibited no(2) and n(2)o production from nh(4) in incubations of n. europaea, while lower concentrations of these gases resulted in partial inhibition. oxidation of hydroxylamine (nh(2)oh) by n. europaea and oxidation of no(2) by a nitrobacter s ...199316349011
close genetic relationship between nitrobacter hamburgensis nitrite oxidoreductase and escherichia coli nitrate reductases.the nitrite oxidoreductase (nor) from the facultative nitrite-oxidizing bacterium nitrobacter hamburgensis x14 was investigated genetically. in order to develop a probe for the gene norb, the n-terminal amino acid sequence of the nor beta-subunit (norb) was determined. based on that amino acid sequence, an oligonucleotide was derived that was used for the identification and cloning of gene norb. sequence analysis of dna fragments revealed three adjacent open reading frames in the order nora, nor ...19938297210
membrane-bound cytochrome c is an alternative electron donor for cytochrome aa3 in nitrobacter winogradskyi.we purified membrane-bound cytochrome c-550 [cytochrome c-550(m)] to an electrophoretically homogeneous state from nitrobacter winogradskyi. the cytochrome showed peaks at 409 and 525 nm in the oxidized form and peaks at 416, 521, and 550 nm in the reduced form. the molecular weight of the cytochrome was estimated to be 18,400 on the basis of protein and heme c contents and 18,600 by gel filtration. the n-terminal amino acid sequence of cytochrome c-550(m) was determined to be a-p-t-s-a-a-d-a-e- ...19938392510
effect of nematicides, telone ii and vorlex, on microflora and nitrification in tobacco soil. 19938418937
biotreatment of ammonia- and butanal-containing waste gases.the biological removal of ammonia and butanal in contaminated air was investigated by using, respectively, a laboratory-scale filter and a scrubber-filter combination. it was shown that ammonia can be removed with an elimination efficiency of 83% at a volumetric load of 100 m3.m-2.h-1 with 4-16 ppm of ammonia. during the experiment percolates were analysed for nitrate, nitrite, ammonium and ph. it was found that the nitrification in the biofilter could deteriorate due to an inhibition of nitroba ...19947765814
[the endotoxins of gram-negative bacteria: their structure and biological role].main attention in the paper is paid to the study of lipid a, a component possessing endotoxic activity. lipids a containing glucosamine disaccharide (representatives of enterobacteriaceae family), and variants of lipid a differing from the toxic one either in the structure of carbohydrate core or in the spectrum of fatty acids are considered. they are either phototrophic, nodulating (bradyrhyzobium species) or soil species (nitrobacter and thiobacillus) bacteria. lipid a from lipopolysaccharides ...19947952230
evolutionary relationships among ammonia- and nitrite-oxidizing bacteria.comparative 16s rrna sequencing was used to evaluate phylogenetic relationships among selected strains of ammonia- and nitrite-oxidizing bacteria. all characterized strains were shown to be affiliated with the proteobacteria. the study extended recent 16s rrna-based studies of phylogenetic diversity among nitrifiers by the comparison of eight strains of the genus nitrobacter and representatives of the genera nitrospira and nitrospina. the later genera were shown to be affiliated with the delta s ...19947961414
iron metabolism in rhodobacter capsulatus. characterisation of bacterioferritin and formation of non-haem iron particles in intact cells.the water-soluble cytochrome b557 from the photosynthetic bacterium rhodobacter capsulatus was purified and shown to have the properties of the iron-storage protein bacterioferritin. the molecular mass of r. capsulatus bacterioferritin is 428 kda and it is composed of a single type of 18-kda subunit. the n-terminal amino acid sequence of the bacterioferritin subunit shows 70% identity to the sequence of bacterioferritin subunits from escherichia coli, nitrobacter winogradskyi, azotobacter vinela ...19948055962
effects of herbicides and fumigants on microbial activities in soil. 19948069060
molecular phylogenetic analysis of nitrobacter spp.the phylogeny of bacteria belonging to the genus nitrobacter was investigated by sequencing the whole 16s rrna gene. the average level of similarity for the three nitrobacter strains examined was high (99.2%), and the similarity level between nitrobacter winogradskyi and nitrobacter sp. strain ll, which represent two different genomic species, was even higher (99.6%). when all of the nitrobacter strains and their phylogenetic neighbors bradyrhizobium and rhodopseudomonas species were considered, ...19948123564
tolerance of nitrobacter to toxicity of some nigerian crude oils. 19948142709
biological nitrogen removal from wastewater.a review of the research on the kinetics of nitrification and denitrification is presented including an explanation of reaction engineering models. the results of laboratory scale experiments with high rate nitrification processes are discussed using kinetic results for oxygen limitation as well as for substrate limitation and inhibition. it can be demonstrated that reaction engineering models are helpful for a better understanding of the processes and for the design of reactors. pilot scale inv ...19948165950
co-immobilized nitrosomonas europaea and nitrobacter agilis cells: validation of a dynamic model for simultaneous substrate conversion and growth in kappa-carrageenan gel beads.a dynamic model for two microbial species immobilized in a gel matrix is presented and validated with experiments. the model characterizes the nitrification of ammonia with nitrosomonas europaea and nitrobacter agilis co-immobilized in k-carrageenan gel beads. the model consists of kinetic equations for the microorganisms and mass transfer equations for the substrates and products inside and outside the gel beads. the model predicts reactor bulk concentrations together with the substrate consump ...199418615529
effects of diffusion limitation on immobilized nitrifying microorganisms at low temperatures.activation energies of suspended and immobilized nitrifying bacteria were determined and compared to determine if diffusion limitation results in decreased sensitivity for temperature. the activation energy for the respiration activity of suspended nitrosomonas europaea and nitrobacter agilis was found to be 86.4 and 58.4 kj mol(-1), respectively. the activation energy for oxygen diffusion in the support material, kappa-carrageenan, determined from the effect of temperature on the effective diff ...199518623045
genetic and phenetic analyses of bradyrhizobium strains nodulating peanut (arachis hypogaea l.) roots.seventeen bradyrhizobium sp. strains and one azorhizobium strain were compared on the basis of five genetic and phenetic features: (i) partial sequence analyses of the 16s rrna gene (rdna), (ii) randomly amplified dna polymorphisms (rapd) using three oligonucleotide primers, (iii) total cellular protein profiles, (iv) utilization of 21 aliphatic and 22 aromatic substrates, and (v) intrinsic resistances to seven antibiotics. partial 16s rdna analysis revealed the presence of only two rdna homolog ...19957538280
a new obligately chemolithoautotrophic, nitrite-oxidizing bacterium, nitrospira moscoviensis sp. nov. and its phylogenetic relationship.a gram-negative, non-motile, non-marine, nitrite-oxidizing bacterium was isolated from an enrichment culture initiated with a sample from a partially corroded area of an iron pipe of a heating system in moscow, russia. the cells were 0.9-2.2 microns x 0.2-0.4 microns in size. they were helical- to vibroid-shaped and often formed spirals with up to three turns 0.8-1.0 micron in width. the organism possessed an enlarged periplasmic space and lacked intracytoplasmic membranes and carboxysomes. the ...19957646315
detection and counting of nitrobacter populations in soil by pcr.although the biological conversion of nitrite to nitrate is a well-known process, studies of nitrobacter populations are hindered by their physiological characteristics. this report describes a new method for detecting and counting nitrobacter populations in situ with the pcr. two primers from the 16s rrna gene were used to generate a 397-bp fragment by amplification of nitrobacter species dna. no signal was detected from their phylogenetic neighbors or the common soil bacteria tested. extractio ...19957793930
a bioreactor system for the nitrogen loop in a controlled ecological life support system.as space missions become longer in duration, the need to recycle waste into useful compounds rises dramatically. this problem can be addressed by the development of controlled ecological life support systems (celss) (i.e., engineered closed/controlled eco-systems (ecces)), consisting of human and plant modules. one of the waste streams leaving the human module is urine. in addition to the reclamation of water from urine, recovery of the nitrogen is important because it is an essential nutrien ...199611538973
monoclonal antibodies recognizing nitrite oxidoreductase of nitrobacter hamburgensis, n. winogradskyi, and n. vulgaris.three monoclonal antibodies (mabs) against nitrite oxidoreductase (nor) of nitrobacter hamburgensis were produced. sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analysis of the purified enzyme showed that the mabs named hyb 153.1 and hyb 153.3 both recognized a protein with a molecular mass of 64,000 da, while hyb 153.2 recognized a protein with a molecular mass of 115,000 da. the molecular masses of these proteins are in the same range as those of the proteins of ...19968779572
phylogenetic probes for analyzing abundance and spatial organization of nitrifying bacteria.a hierarchical set of five 16s rrna-targeted oligonucleotide dna probes for phylogenetically defined groups of autotrophic ammonia- and nitrite-oxidizing bacteria was developed for environmental and determinative studies. hybridization conditions were established for each probe by using temperature dissociation profiles of target and closely related nontarget organisms to document specificity. environmental application was demonstrated by quantitative slot blot hybridization and whole-cell hybri ...19968787412
nitrobacter winogradskyi cytochrome c oxidase genes are organized in a repeated gene cluster.cytochrome c oxidase (ec 1.9.3.1) is one of the components of the electron transport chain by which nitrobacter, a facultative lithoautotrophic bacterium, recovers energy from nitrite oxidation. the genes encoding the two catalytic core subunits of the enzyme were isolated from a nitrobacter winogradskyi gene library. sequencing of one of the 14 cloned dna segments revealed that the subunit genes are side by side in an operon-like cluster. remarkably the cluster appears to be present in at least ...19968836428
structure and function of a nitrifying biofilm as determined by in situ hybridization and the use of microelectrodes.microprofiles of o2 and no3- were measured in nitrifying biofilms from the trickling filter of an aquaculture water recirculation system. by use of a newly developed biosensor for no3-, it was possible to avoid conventional interference from other ions. nitrification was restricted to a narrow zone of 50 microns on the very top of the film. in the same biofilms, the vertical distributions of members of the lithoautotrophic ammonia-oxidizing genus nitrosomonas and of the nitrite-oxidizing genus n ...19968953735
steady-state solution of a two-species biofilm problem.through a thorough investigation of the boundary conditions for a general two-species biofilm model, a simple and fast method for solving the steady-state case is developed and presented. the methods used may be extended to biofilm models in which more than two species are considered. four different sets of boundary conditions are possible for the two-species biofilm model. each set is shown to be asymptotically stable. a biofilm model describing the competition between autotrophic and heterotro ...199618627076
production of no and n(inf2)o by pure cultures of nitrifying and denitrifying bacteria during changes in aeration.peak emissions of no and n(inf2)o are often observed after wetting of soil. the reactions to sudden changes in the aeration of cultures of nitrifying and denitrifying bacteria with respect to no and n(inf2)o emissions were compared to obtain more information about the microbiological aspects of peak emissions. in continuous culture, the nitrifier nitrosomonas europaea and the denitrifiers alcaligenes eutrophus and pseudomonas stutzeri were cultured at different levels of aeration (80 to 0% air s ...199716535707
dissimilatory nitrate reduction in anaerobic sediments leading to river nitrite accumulation.recent studies on northern ireland rivers have shown that summer nitrite (no(inf2)(sup-)) concentrations greatly exceed the european union guideline of 3 (mu)g of n liter(sup-1) for rivers supporting salmonid fisheries. in fast-flowing aerobic small streams, no(inf2)(sup-) is thought to originate from nitrification, due to the retardation of nitrobacter strains by the presence of free ammonia. multiple regression analyses of no(inf2)(sup-) concentrations against water quality variables of the si ...199716535749
isolation and immunocytochemical location of the nitrite-oxidizing system in nitrospira moscoviensisa membrane-associated nitrite-oxidizing system of nitrospira moscoviensis was isolated from heat-treated membranes. the four major proteins of the enzyme fraction had apparent molecular masses of 130, 62, 46, and 29 kda, respectively. the nitrite-oxidizing activity was dependent on the presence of molybdenum. in contrast to the nitrite oxidoreductase of nitrobacter hamburgensis x14, the activity of the nitrite-oxidizing system of ns. moscoviensis increased when solubilized by heat treatment. ele ...19989477257
microbiology of a nitrite-oxidizing bioreactor.the microbiology of the biomass from a nitrite-oxidizing sequencing batch reactor (nosbr) fed with an inorganic salts solution and nitrite as the sole energy source that had been operating for 6 months was investigated by microscopy, by culture-dependent methods, and by molecular biological methods, and the seed sludge that was used to inoculate the nosbr was investigated by molecular biological methods. the nosbr sludge comprised a complex and diverse microbial community containing gram-negativ ...19989572966
combined molecular and conventional analyses of nitrifying bacterium diversity in activated sludge: nitrosococcus mobilis and nitrospira-like bacteria as dominant populations.the ammonia-oxidizing and nitrite-oxidizing bacterial populations occurring in the nitrifying activated sludge of an industrial wastewater treatment plant receiving sewage with high ammonia concentrations were studied by use of a polyphasic approach. in situ hybridization with a set of hierarchical 16s rrna-targeted probes for ammonia-oxidizing bacteria revealed the dominance of nitrosococcus mobilis-like bacteria. the phylogenetic affiliation suggested by fluorescent in situ hybridization (fish ...19989687471
identification and activities in situ of nitrosospira and nitrospira spp. as dominant populations in a nitrifying fluidized bed reactor.bacterial aggregates from a chemolithoautotrophic, nitrifying fluidized bed reactor were investigated with microsensors and rrna-based molecular techniques. the microprofiles of o2, nh4+, no2-, and no3- demonstrated the occurrence of complete nitrification in the outer 125 microgram of the aggregates. the ammonia oxidizers were identified as members of the nitrosospira group by fluorescence in situ hybridization (fish). no ammonia- or nitrite-oxidizing bacteria of the genus nitrosomonas or nitro ...19989726900
isolation and characterization of a novel facultatively alkaliphilic nitrobacter species, n. alkalicus sp. nov.five strains of lithotrophic, nitrite-oxidizing bacteria (an1-an5) were isolated from sediments of three soda lakes (kunkur steppe, siberia; crater lake and lake nakuru, kenya) and from a soda soil (kunkur steppe, siberia) after enrichment at ph 10 with nitrite as sole electron source. morphologically, the isolates resembled representatives of the genus nitrobacter. however, they differed from recognized species of this genus by the presence of an additional s-layer in their cell wall and by the ...19989818354
organic halogen removal from chlorinated humic ground water and lake water by nitrifying fluidized-bed biomass characterised by electron microscopy and molecular methods.the dechlorinating and genotoxicity-removing activities of nitrifying fluidized-bed reactor biomass towards chlorinated organic compounds in water were shown at level below 1 ppm. the removal rates of adsorbable organic halogens were 200 micrograms cl (g vs day)-1 for chlorinated humic ground water and 50 micrograms cl (g vs day)-1 for chlorinated lake water when studied in batch mode. in a sequenced batch mode the removal rates [micrograms cl (g vs day)-1] were 2000 from chlorohumus, 1400-1800 ...19989866179
an amperometric enzyme-linked immunosensor for nitrobacter.a new amperometric enzyme-linked immunoassay for specific enumeration of nitrobacter has been developed. this assay uses an electrode made of glassy carbon, on which the immunological reaction is carried out. the method is based on a competitive immunoassay principle, utilising monoclonal primary antibody and alkaline-phosphatase-labelled secondary antibody. the enzyme substrate 5-bromo-4-chloro-3-indolyl phosphate generates an electroactive product which is amperometrically detected. the effect ...19989891931
water purification system by using the biofilter for long-term experiment equipment with aquatic animals for the space station.we have developed a water purification system that enables long-term experiment with aquatic animals for 90 days or more on the space station. we designed the system that combined a biofilter for ammonia removal (nitrification) with another for nitrate removal (denitrification). the experiment with goldfish was for 90 days with an aquatic animals' examination device. the equipment consists of a fish tank, a filter module, pumps, and an artificial lung for gas exchange. the goldfish were kept in ...199811876203
nitrospira-like bacteria associated with nitrite oxidation in freshwater aquaria.oxidation of nitrite to nitrate in aquaria is typically attributed to bacteria belonging to the genus nitrobacter which are members of the alpha subdivision of the class proteobacteria. in order to identify bacteria responsible for nitrite oxidation in aquaria, clone libraries of rrna genes were developed from biofilms of several freshwater aquaria. analysis of the rdna libraries, along with results from denaturing gradient gel electrophoresis (dgge) on frequently sampled biofilms, indicated the ...199816349486
high mortality in zebrafish (danio rerio).a group of 100 adult zebrafish were housed in a new system at a stocking density of 20 fish per tank. four weeks after arrival, 15 fish presented with petechial hemorrhages and ulceration on the surfaces of the skin. samples of the fish were collected for histopathology, fungal culture, and bacterial culture and sensitivity. water samples were analyzed for ph, ammonia, nitrite, and submitted for bacterial and fungal culture. histologically, the epidermis had multiple areas of ulceration and mono ...199912086431
[vfeu water quality control in sts-95 aquatic animal experiment]. 199912533005
taxon-specific content of oligonucleotide triplets in 16s rrnas of anoxygenic phototrophic and nitrifying bacteria.theoretical evaluation of the content of oligonucleotide triplets aaa, ccc, and uau in 16s rrnas of anoxygenic phototrophic bacteria (genera chlorobium; chloroflexus; chromatium: rhodopseudomonas) and nitrifying bacteria (genera nitrosococcus, nitrosomonas, nitrosolobus, nitrosovibrio, nitrospira, nitrospina, nitrobacter) showed that the number of the aaa, ccc or uau triplets in 16s rrnas specifically corresponds to the genus and species of bacteria. the ratio of aaa and ccc triplet numbers in t ...199910049622
assessment of three methods for detection and quantification of nitrite-oxidizing bacteria and nitrobacter in freshwater sediments (mpn-pcr, mpn-griess, immunofluorescence).> abstract nitrification in freshwater, a key process in the nitrogen cycle, is now well known to take place predominantly on suspended particles and in sediment. nitrobacter is the most commonly isolated nitrite oxidizing bacteria from water environments. three methods for counting nitrite oxidizing communities (especially nitrobacter) in sediment were investigated: mpn-griess, fluorescent antibodies (immunofluorescence), and a more recent molecular method coupling specific dna amplification by ...199910227878
maintenance energy demand and starvation recovery dynamics of nitrosomonas europaea and nitrobacter winogradskyi cultivated in a retentostat with complete biomass retention.nitrosomonas europaea and nitrobacter winogradskyi (strain "engel") were grown in ammonia-limited and nitrite-limited conditions, respectively, in a retentostat with complete biomass retention at 25 degrees c and ph 8. fitting the retentostat biomass and oxygen consumption data of n. europaea and n. winogradskyi to the linear equation for substrate utilization resulted in up to eight-times-lower maintenance requirements compared to the maintenance energy demand (m) calculated from chemostat expe ...199910347029
in situ analysis of nitrifying biofilms as determined by in situ hybridization and the use of microelectrodes.we investigated the in situ spatial organization of ammonia-oxidizing and nitrite-oxidizing bacteria in domestic wastewater biofilms and autotrophic nitrifying biofilms by using microsensors and fluorescent in situ hybridization (fish) performed with 16s rrna-targeted oligonucleotide probes. the combination of these techniques made it possible to relate in situ microbial activity directly to the occurrence of nitrifying bacterial populations. in situ hybridization revealed that bacteria belongin ...199910388720
identification of nitrite-oxidizing bacteria with monoclonal antibodies recognizing the nitrite oxidoreductase.immunoblot analyses performed with three monoclonal antibodies (mabs) that recognized the nitrite oxidoreductase (nor) of the genus nitrobacter were used for taxonomic investigations of nitrite oxidizers. we found that these mabs were able to detect the nitrite-oxidizing systems (nos) of the genera nitrospira, nitrococcus, and nitrospina. the mab designated hyb 153-2, which recognized the alpha subunit of the nor (alpha-nor), was specific for species belonging to the genus nitrobacter. in contra ...199910473425
vfeu water quality control in sts-95 mission.in sts-95 space shuttle mission, an aquatic animal research facility, vestibular function experiment unit (vfeu), was flown to perform neurobiological experiment with marine fish, oyster toadfish. for this purpose, we have developed a sea water purification system using highly active nitrifying bacteria at low temperature. with this system, the water quality in the vfeu was maintained in sufficient condition to keep the toadfish in healthy state for 9 days of the mission. this report summarizes ...199911542797
water quality management for low temperature marine fishes in space.vestibular function experiment unit (vfeu), one of the spacelab facility flown in neurolab mission (sts-90) in april, 1998, was to support neurophysiological research using a marine fish, opsanus tau (oyster toadfish). the functions of the vfeu were primarily a quality management of environmental water during the mission at 14 degrees c and for acquiring physiological signals from implanted micro-electrodes in the otolith nerves as well as the spatial acceleration of the fish. a key element of t ...199911542798
r&d of long-term life support system by using electrochemically activated biofilm reactor of aquatic animals for space examinations.we have developed the long-term life support system that enables the experiment of aquatic animals breeding for 90 days or more for the future experiments in orbit. in order to enable long-term breeding of wide aquatic animals, it is necessary to remove nitrate produced by biological nitrification. then, we examined a denitrification method to use an electrochemical reaction of biofilm-electrode reactor. in this research, we have not kept the aquatic animals actually but imitated breeding of fiv ...199911542801
microenvironments and distribution of nitrifying bacteria in a membrane-bound biofilm.the distribution of nitrifying bacteria of the genera nitrosomonas, nitrosospira, nitrobacter and nitrospira was investigated in a membrane-bound biofilm system with opposed supply of oxygen and ammonium. gradients of oxygen, ph, nitrite and nitrate were determined by means of microsensors while the nitrifying populations along these gradients were identified and quantified using fluorescence in situ hybridization (fish) in combination with confocal laser scanning microscopy. the oxic part of th ...200011214800
microscale diversity of the genus nitrobacter in soil on the basis of analysis of genes encoding rrna.we looked at the diversity of [no(2)](-) oxidizers at field scale by examining isolates at clump scale and in microsamples of soil (diameter, 50 microm). the genetic distances (as determined by amplified ribosomal dna restriction analysis performed with nitrobacter-specific primers) in a small clump of soil were as large as those between reference strains from large geographical areas. diversity in individual microsamples was shown by serotyping.200011010914
application of an amperometric immunosensor for the enumeration of nitrobacter in activated sludge.a competitive immunosensor using a monoclonal antibody has been developed for the enumeration of nitrobacter in activated sludge and other environmental samples. its cross-reactivity was tested against a number of bacterial strains and isolates. all strains of the nitrite-oxidising genera nitrobacter and nitrococcus reacted strongly with the monoclonal antibody. the nitrite-oxidising nitrospira moscoviensis, as well as the ammonia oxidising bacteria and the heterotrophic bacteria tested, did not ...200011030580
high-resolution phylogenetic analysis of no2--oxidizing nitrobacter species using the rrs-rrl igs sequence and rrl genes.a high-resolution phylogenetic analysis of nitrobacter strains and their neighbours was made using the rrs-rrl intergenic spacer sequence and the hypervariable part of the rrl gene. the phylogenetic tree obtained was consistent with that which was obtained previously but was much more discriminating, permitting the design of genus-specific primers.200011034501
energy model and metabolic flux analysis for autotrophic nitrifiers.the behavior of pure cultures of nitrifying microorganisms under autotrophic growth operating conditions was investigated and the relations between their energy metabolism and their anabolism analyzed by means of metabolic network computation. the description of the metabolism of the nitrifiers is extended to their energy metabolism by introducing compartmentalization (cytoplasmic and periplasmic sides) and studying coupling between the electron transport chain and the proton gradient generation ...200111180062
phylogenetic and dna-dna hybridization analyses of bradyrhizobium species.the 16s rdna sequence of bradyrhizobium liaoningense was determined and analysed together with sequences of other bradyrhizobium species and related taxa. in addition, dna-dna hybridizations were performed between representative strains of the three bradyrhizobium species. bradyrhizobium liaoningense is genotypically highly related to bradyrhizobium japonicum, whereas bradyrhizobium elkanii is more distantly related to these two species. the fact that afipia, agromonas, blastobacter, nitrobacter ...200111211247
development of nitrification inhibition assays using pure cultures of nitrosomonas and nitrobacter.restricted requirements for nitrogen reduction at wastewater treatment plants have increased the need for assays determining the inhibition of nitrification. in this paper, two new assays studying ammonia oxidation and nitrite oxidation, respectively, are presented. as test organisms, pure cultures of nitrosomonas and nitrobacter isolated from activated sludge are used. the assays are performed in test tubes where the bacteria are incubated with the compound or wastewater to be tested. the nitri ...200111228996
simultaneous carbon and nitrogen removal from high strength domestic wastewater in an aerobic rbc biofilm.high strength domestic wastewater discharges after no/partial treatment through sewage treatment plants or septic tank seepage field systems have resulted in a large build-up of groundwater nitrates in rajasthan, india. the groundwater table is very deep and nitrate concentrations of 500-750 mg/l (113-169 as no3(-)-n) are commonly found. a novel biofilm in a 3-stage lab-scale rotating biological contactor (rbc) was developed by the incorporation of a sulphur oxidising bacterium thiosphaera panto ...200111329673
nitrogen transformation during organic waste composting by the rutgers system and its effects on ph, ec and maturity of the composting mixtures.the evolution of the different forms of nitrogen during the composting of several wastes was studied, as well as its relation to the ph, electrical conductivity and parameters of maturity of the composts obtained. four mixtures were prepared from different organic materials: sewage sludge, municipal solid waste, brewery sludge, sorghum bagasse, cotton waste and pine bark. the evolution of the different forms of nitrogen during composting depended on the material which supplied the nitrogen to th ...200111341692
implementation, study and calibration of a modified asm2d for the simulation of sbr processes.an enhanced process model for sbrs has been developed. though the basic mechanism largely draws on the activated sludge model n. 2d, its new features are the splitting of the nitrification stage in a two-step process, according to the well known nitrosomonas-nitrobacter oxidation sequence, and an improved xpao dynamics, involved in the anaerobic/aerobic phosphorus removal process. the model was implemented through the dll technique allowing complied c++ modules to be linked to an ordinary simuli ...200111381934
enhancement of nitrifying biofilm formation using selected eps produced by heterotrophic bacteria.the possibility of enhancing nitrifying biofilm formation rate with the aid of selected eps produced by heterotrophic bacteria was investigated. when eps production characteristics were examined for four kinds of heterotrophs isolated from a domestic wastewater treatment reactor, two strains obtained from biofilms (b1, b2) exhibited a higher polysaccharide production rate than those from suspended flocs (a1, a2). among eps components, the concentration of uronic acids gave a good correlation wit ...200111381968
analysis of microbial structure and function of nitrifying biofilms. 200111398431
in situ reverse transcription to detect the cbbl gene and visualize rubisco in chemoautotrophic nitrifying bacteria.in situ methodologies targeting the cbbl gene were used to visualize cells of nitrifying bacteria. both procaryotic in situ pcr (is-pcr) and in situ reverse transcription (isrt) protocols were employed to determine gene presence and expression, respectively.200111412349
soft particle analysis of bacterial cells and its interpretation of cell adhesion behaviors in terms of dlvo theory.the electrokinetic properties of two nitrifying strains, nitrosomonas europaea and nitrobacter winogradskyi, and three heterotrophic bacteria, escherichia coli, pseudomonas putida and pseudomonas aeruginosa, were examined by electrophoretic mobility measurement and analyzed using the soft particle electrophoresis theory that is suitable for biological particles. the bacterial adhesion characteristics onto glass bead substratum were also evaluated by packed bed method. the mobility of the bacteri ...200111451661
factors affecting nitrite build-up in nitrifying biofilm reactor.nitrite build-up in a nitrifying biofilm reactor for direct denitrification from the nitrite stage was investigated. at least three factors were found to influence the nitrite build-up: (i) the relative specific growth rates of nitrosomonas to nitrobacter, microns/micronb in the biofilm; (ii) the relative initial ratio between nitrosomonas and nitrobacter on the support surface, (mao)ns/(mao)nb; (iii) the level of free ammonia, particularly at greater than 0.1 mg n/l that can be inhibitory to ni ...200111501303
activity monitoring for nitrifying bacteria by fluorescence in situ hybridization and respirometry.the activities of two families of nitrifying bacteria were measured by applied respirometer and fluorescence in situ hybridization (fish) for the purpose of monitoring nitrogen removal. oxygen uptake rates (our) for nitrosomonas and nitrobacter were separately measured with the dosing of selective inhibitors during respirometric monitoring. the fish method was applied to analyze microorganism communities. in 5 mg nh4+-n/l solution, the total nitrogen oxygen demand (nod) was found to be 6,672 mg ...200111516017
ammonia-oxidizing bacteria: a model for molecular microbial ecology.the eutrophication of many ecosystems in recent decades has led to an increased interest in the ecology of nitrogen transformation. chemolitho-autotrophic ammonia-oxidizing bacteria are responsible for the rate-limiting step of nitrification in a wide variety of environments, making them important in the global cycling of nitrogen. these organisms are unique in their ability to use the conversion of ammonia to nitrite as their sole energy source. because of the importance of this functional grou ...200111544365
potential nitrification rate as a tool for screening toxicity in metal-contaminated soils.a potential nitrification rate test (pnr) was used to identify metal toxicity in field-contaminated soils. the test was applied to metal salt-spiked soils, to 27 uncontaminated soils, and to 15 soils that are contaminated by former metal smelting activities. four agricultural soils (ph 4.5-6.6) were spiked with various rates of cdcl2 (0-200 mg cd/kg dry wt) or zncl2 (0-3,000 mg cd/kg dry wt) and were equilibrated more than nine months prior to testing. the soil zn ec50s of the pnr were between 1 ...200111699771
the canon system (completely autotrophic nitrogen-removal over nitrite) under ammonium limitation: interaction and competition between three groups of bacteria.the canon system (completely autotrophic nitrogen removal over nitrite) can potentially remove ammonium from wastewater in a single, oxygen-limited treatment step. the usefulness of canon as an industrial process will be determined by the ability of the system to recover from major disturbances in feed composition. the canon process relies on the stable interaction between only two bacterial populations: nitrosomonas-like aerobic and planctomycete-like anaerobic ammonium oxidising bacteria. the ...200111876366
fatty acid profiles of nitrite-oxidizing bacteria reflect their phylogenetic heterogeneity.the fatty acid profiles of all described species of the nitrite-oxidizing genera nitrobacter, nitrococcus, nitrospina and nitrospira were analyzed. the four genera had distinct profiles, which can be used for the differentiation and allocation of new isolates to these genera. the genus nitrobacter is characterized by vaccenic acid as the main compound with up to 92% of the fatty acids and the absence of hydroxy fatty acids. the genus nitrococcus showed cis-9-hexadecenoic acid, hexadecanoic acid ...200111822673
the aquatic budding bacterium blastobacter denitrificans is a nitrogen-fixing symbiont of aeschynomene indica.blastobacter spp. are freshwater bacteria that form rosette structures by cellular attachment to a common base. comparative analyses of ribosomal 16s rrna gene and internally transcribed spacer region sequences indicated that b. denitrificans is a member of the alpha-subdivision of proteobacteria. among the alpha-proteobacteria, b. denitrificans was related to a cluster of genera, including rhodopseudomonas palustris, afipia felis, nitrobacter hamburgensis, and bradyrhizobium spp. although the p ...200211872460
immunological detection of nitrospira-like bacteria in various soils.chemolithotrophic nitrite oxidizers were enriched from five different soils including freshwater marsh, permafrost, garden, agricultural, and desert soils and monitored during the cultivation procedure. immunoblot analysis was used to identify the nitrite oxidizing organisms with monoclonal antibodies, which recognize the key enzyme of nitrite oxidation in a genus-specific reaction [bartosch et al. (1999) appl environ microbiol 65:4126-4133]. the morphological characteristics of the enriched nit ...200211984626
isolation and characterization of cbbl and cbbs genes encoding form i ribulose-1,5-bisphosphate carboxylase/oxygenase large and small subunits in nitrosomonas sp. strain eni-11.the cbbl and cbbs genes encoding form i ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) large and small subunits in the ammonia-oxidizing bacterium nitrosomonas sp. strain eni-11 were cloned and sequenced. the deduced gene products, cbbl and cbbs, had 93 and 87% identity with thiobacillus intermedius cbbl and nitrobacter winogradskyi cbbs, respectively. expression of cbbl and cbbs in escherichia coli led to the detection of rubisco activity in the presence of 0.1 mm isopropyl-beta-d-th ...200212005060
intestinal urea metabolism: could the bacteria involved in nitrogen cycle lead to reutilization of intestinal urea nitrogen in uremic rabbits?we aimed to evaluate the effect of bacteria involved in the nitrogen cycle on the reutilization of intestinal urea nitrogen in uremic rabbits. new zealand white rabbits were made uremic via bilateral nephrectomy. study and control rabbits were given live and heat-inactivated bacteria through their jejunostomies. after they were injected with 99mtc biurea intravenously, serial serum and stool levels of labeled nitrogen were assessed by instant thin-layer chromatography, and the change in the labe ...200212026184
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